Inferred division from defined multiplication relations (#1354)

In
[#1329](#1329 (comment))
this proposal came up:

> Another idea: generate division operators based on multiplication.
Right now we define:
> ```
> ElectricPotential.Volt = ElectricCurrent.Ampere *
ElectricResistance.Ohm (and generate the reverse)
> ElectricCurrent.Ampere = ElectricPotential.Volt /
ElectricResistance.Ohm
> ElectricResistance.Ohm = ElectricPotential.Volt /
ElectricCurrent.Ampere
> ```
> But those last two could also be generated based on the first.

This PR is an experiment implementing this.

### Breaking changes:

- `TimeSpan = Volume / VolumeFlow` => `Duration = Volume / VolumeFlow`

Author: Muximize

CodeGen/Generators/QuantityRelationsParser.cs

@@ -25,13 +25,16 @@ internal static class QuantityRelationsParser
         ///
         ///     The format of a relation definition is "Quantity.Unit operator Quantity.Unit = Quantity.Unit" (See examples below).
         ///     "double" can be used as a unitless operand.
-        ///     "1" can be used as the left operand to define inverse relations.
+        ///     "1" can be used as the result operand to define inverse relations.
+        ///
+        ///     Division relations are inferred from multiplication relations,
+        ///     but this can be skipped if the string ends with "NoInferredDivision".
         /// </summary>
         /// <example>
         /// [
-        ///     "Power.Watt = ElectricPotential.Volt * ElectricCurrent.Ampere",
-        ///     "Speed.MeterPerSecond = Length.Meter / Duration.Second",
-        ///     "ReciprocalLength.InverseMeter = 1 / Length.Meter"
+        ///   "1 = Length.Meter * ReciprocalLength.InverseMeter"
+        ///   "Power.Watt = ElectricPotential.Volt * ElectricCurrent.Ampere",
+        ///   "Mass.Kilogram = MassConcentration.KilogramPerCubicMeter * Volume.CubicMeter -- NoInferredDivision",
         /// ]
         /// </example>
         /// <param name="rootDir">Repository root directory.</param>
@@ -58,10 +61,25 @@ public static void ParseAndApplyRelations(string rootDir, Quantity[] quantities)
                     RightUnit = r.LeftUnit,
                 })
                 .ToList());
+            
+            // We can infer division relations from multiplication relations.
+            relations.AddRange(relations
+                .Where(r => r is { Operator: "*", NoInferredDivision: false })
+                .Select(r => r with
+                {
+                    Operator = "/",
+                    LeftQuantity = r.ResultQuantity,
+                    LeftUnit = r.ResultUnit,
+                    ResultQuantity = r.LeftQuantity,
+                    ResultUnit = r.LeftUnit,
+                })
+                // Skip division between equal quantities because the ratio is already generated as part of the Arithmetic Operators.
+                .Where(r => r.LeftQuantity != r.RightQuantity)
+                .ToList());
 
             // Sort all relations to keep generated operators in a consistent order.
             relations.Sort();
-            
+
             var duplicates = relations
                 .GroupBy(r => r.SortString)
                 .Where(g => g.Count() > 1)
@@ -73,6 +91,18 @@ public static void ParseAndApplyRelations(string rootDir, Quantity[] quantities)
                 var list = string.Join("\n  ", duplicates);
                 throw new UnitsNetCodeGenException($"Duplicate inferred relations:\n  {list}");
             }
+            
+            var ambiguous = relations
+                .GroupBy(r => $"{r.LeftQuantity.Name} {r.Operator} {r.RightQuantity.Name}")
+                .Where(g => g.Count() > 1)
+                .Select(g => g.Key)
+                .ToList();
+
+            if (ambiguous.Any())
+            {
+                var list = string.Join("\n  ", ambiguous);
+                throw new UnitsNetCodeGenException($"Ambiguous inferred relations:\n  {list}\n\nHint: you could use NoInferredDivision in the definition file.");
+            }
 
             foreach (var quantity in quantities)
             {
@@ -122,7 +152,7 @@ private static QuantityRelation ParseRelation(string relationString, IReadOnlyDi
         {
             var segments = relationString.Split(' ');
 
-            if (segments is not [_, "=", _, "*" or "/", _])
+            if (segments is not [_, "=", _, "*", _, ..])
             {
                 throw new Exception($"Invalid relation string: {relationString}");
             }
@@ -140,15 +170,14 @@ private static QuantityRelation ParseRelation(string relationString, IReadOnlyDi
             var rightUnit = GetUnit(rightQuantity, right.ElementAtOrDefault(1));
             var resultUnit = GetUnit(resultQuantity, result.ElementAtOrDefault(1));
 
-            if (leftQuantity.Name == "1")
+            if (resultQuantity.Name == "1")
             {
                 @operator = "inverse";
-                leftQuantity = resultQuantity;
-                leftUnit = resultUnit;
             }
 
             return new QuantityRelation
             {
+                NoInferredDivision = segments.Contains("NoInferredDivision"),
                 Operator = @operator,
                 LeftQuantity = leftQuantity,
                 LeftUnit = leftUnit,

CodeGen/JsonTypes/QuantityRelation.cs

@@ -7,6 +7,7 @@ namespace CodeGen.JsonTypes
 {
     internal record QuantityRelation : IComparable<QuantityRelation>
     {
+        public bool NoInferredDivision = false;
         public string Operator = null!;
 
         public Quantity LeftQuantity = null!;

Common/UnitRelations.json

@@ -1,164 +1,79 @@
 [
-  "Acceleration.MeterPerSecondSquared = Force.Newton / Mass.Kilogram",
-  "Acceleration.MeterPerSecondSquared = SpecificWeight.NewtonPerCubicMeter / Density.KilogramPerCubicMeter",
-  "Acceleration.MeterPerSecondSquared = Speed.MeterPerSecond / Duration.Second",
+  "1 = Area.SquareMeter * ReciprocalArea.InverseSquareMeter",
+  "1 = ElectricResistivity.OhmMeter * ElectricConductivity.SiemensPerMeter",
+  "1 = Length.Meter * ReciprocalLength.InverseMeter",
+  "Acceleration.MeterPerSecondSquared = Jerk.MeterPerSecondCubed * Duration.Second",
   "AmountOfSubstance.Kilomole = MolarFlow.KilomolePerSecond * Duration.Second",
-  "AmountOfSubstance.Mole = Mass.Kilogram / MolarMass.KilogramPerMole",
+  "AmountOfSubstance.Mole = Molarity.MolePerCubicMeter * Volume.CubicMeter",
   "Angle.Radian = RotationalSpeed.RadianPerSecond * Duration.Second",
-  "Angle.Radian = Torque.NewtonMeter / RotationalStiffness.NewtonMeterPerRadian",
   "Area.SquareMeter = KinematicViscosity.SquareMeterPerSecond * Duration.Second",
   "Area.SquareMeter = Length.Meter * Length.Meter",
-  "Area.SquareMeter = LinearDensity.KilogramPerMeter / Density.KilogramPerCubicMeter",
-  "Area.SquareMeter = LuminousIntensity.Candela / Luminance.CandelaPerSquareMeter",
-  "Area.SquareMeter = Mass.Kilogram / AreaDensity.KilogramPerSquareMeter",
-  "Area.SquareMeter = MassFlow.KilogramPerSecond / MassFlux.KilogramPerSecondPerSquareMeter",
-  "Area.SquareMeter = Power.Watt / HeatFlux.WattPerSquareMeter",
-  "Area.SquareMeter = Volume.CubicMeter / Length.Meter",
-  "Area.SquareMeter = VolumeFlow.CubicMeterPerSecond / Speed.MeterPerSecond",
-  "AreaDensity.KilogramPerSquareMeter = Mass.Kilogram / Area.SquareMeter",
-  "BrakeSpecificFuelConsumption.KilogramPerJoule = double / SpecificEnergy.JoulePerKilogram",
-  "BrakeSpecificFuelConsumption.KilogramPerJoule = MassFlow.KilogramPerSecond / Power.Watt",
-  "Density.KilogramPerCubicMeter = double / SpecificVolume.CubicMeterPerKilogram",
-  "Density.KilogramPerCubicMeter = LinearDensity.KilogramPerMeter / Area.SquareMeter",
-  "Density.KilogramPerCubicMeter = Mass.Kilogram / Volume.CubicMeter",
-  "Density.KilogramPerCubicMeter = MassFlow.KilogramPerSecond / VolumeFlow.CubicMeterPerSecond",
-  "Density.KilogramPerCubicMeter = MassFlux.KilogramPerSecondPerSquareMeter / Speed.MeterPerSecond",
-  "Density.KilogramPerCubicMeter = SpecificWeight.NewtonPerCubicMeter / Acceleration.MeterPerSecondSquared",
+  "AreaMomentOfInertia.MeterToTheFourth = Volume.CubicMeter * Length.Meter",
+  "double = Density.KilogramPerCubicMeter * SpecificVolume.CubicMeterPerKilogram",
   "double = SpecificEnergy.JoulePerKilogram * BrakeSpecificFuelConsumption.KilogramPerJoule",
   "double = TemperatureDelta.Kelvin * CoefficientOfThermalExpansion.PerKelvin",
-  "Duration.Hour = ElectricCharge.AmpereHour / ElectricCurrent.Ampere",
-  "Duration.Second = Energy.Joule / Power.Watt",
-  "Duration.Second = Force.Newton / ForceChangeRate.NewtonPerSecond",
-  "Duration.Second = Length.Meter / Speed.MeterPerSecond",
-  "Duration.Second = Speed.MeterPerSecond / Acceleration.MeterPerSecondSquared",
   "DynamicViscosity.NewtonSecondPerMeterSquared = Density.KilogramPerCubicMeter * KinematicViscosity.SquareMeterPerSecond",
   "ElectricCharge.AmpereHour = ElectricCurrent.Ampere * Duration.Hour",
-  "ElectricCharge.Coulomb = Energy.Joule / ElectricPotential.Volt",
-  "ElectricConductivity.SiemensPerMeter = 1 / ElectricResistivity.OhmMeter",
-  "ElectricCurrent.Ampere = ElectricCharge.AmpereHour / Duration.Hour",
   "ElectricCurrent.Ampere = ElectricCurrentGradient.AmperePerSecond * Duration.Second",
-  "ElectricCurrent.Ampere = ElectricPotential.Volt / ElectricResistance.Ohm",
-  "ElectricCurrent.Ampere = Power.Watt / ElectricPotential.Volt",
-  "ElectricCurrentGradient.AmperePerSecond = ElectricCurrent.Ampere / Duration.Second",
   "ElectricPotential.Volt = ElectricCurrent.Ampere * ElectricResistance.Ohm",
-  "ElectricPotential.Volt = Energy.Joule / ElectricCharge.Coulomb",
-  "ElectricPotential.Volt = Power.Watt / ElectricCurrent.Ampere",
-  "ElectricResistance.Ohm = ElectricPotential.Volt / ElectricCurrent.Ampere",
   "Energy.Joule = ElectricPotential.Volt * ElectricCharge.Coulomb",
   "Energy.Joule = EnergyDensity.JoulePerCubicMeter * Volume.CubicMeter",
   "Energy.Joule = Power.Watt * Duration.Second",
   "Energy.Joule = SpecificEnergy.JoulePerKilogram * Mass.Kilogram",
   "Energy.Joule = TemperatureDelta.Kelvin * Entropy.JoulePerKelvin",
-  "Entropy.JoulePerKelvin = Energy.Joule / TemperatureDelta.Kelvin",
   "Entropy.JoulePerKelvin = SpecificEntropy.JoulePerKilogramKelvin * Mass.Kilogram",
   "Force.Newton = ForceChangeRate.NewtonPerSecond * Duration.Second",
   "Force.Newton = ForcePerLength.NewtonPerMeter * Length.Meter",
-  "Force.Newton = ForcePerLength.NewtonPerMeter / ReciprocalLength.InverseMeter",
   "Force.Newton = Mass.Kilogram * Acceleration.MeterPerSecondSquared",
-  "Force.Newton = Power.Watt / Speed.MeterPerSecond",
   "Force.Newton = Pressure.Pascal * Area.SquareMeter",
-  "Force.Newton = Pressure.Pascal / ReciprocalArea.InverseSquareMeter",
-  "Force.Newton = Torque.NewtonMeter / Length.Meter",
   "ForcePerLength.NewtonPerMeter = Force.Newton * ReciprocalLength.InverseMeter",
-  "ForcePerLength.NewtonPerMeter = Force.Newton / Length.Meter",
-  "ForcePerLength.NewtonPerMeter = Pressure.Pascal / ReciprocalLength.InverseMeter",
+  "ForcePerLength.NewtonPerMeter = Pressure.NewtonPerSquareMeter * Length.Meter",
   "ForcePerLength.NewtonPerMeter = SpecificWeight.NewtonPerCubicMeter * Area.SquareMeter",
-  "HeatFlux.WattPerSquareMeter = Power.Watt / Area.SquareMeter",
-  "Jerk.MeterPerSecondCubed = Acceleration.MeterPerSecondSquared / Duration.Second",
-  "KinematicViscosity.SquareMeterPerSecond = DynamicViscosity.NewtonSecondPerMeterSquared / Density.KilogramPerCubicMeter",
   "KinematicViscosity.SquareMeterPerSecond = Length.Meter * Speed.MeterPerSecond",
-  "Length.Kilometer = TemperatureDelta.Kelvin / TemperatureGradient.DegreeCelsiusPerKilometer",
-  "Length.Meter = Area.SquareMeter / Length.Meter",
-  "Length.Meter = Force.Newton / ForcePerLength.NewtonPerMeter",
-  "Length.Meter = Mass.Kilogram / LinearDensity.KilogramPerMeter",
-  "Length.Meter = Pressure.Pascal / SpecificWeight.NewtonPerCubicMeter",
-  "Length.Meter = ReciprocalLength.InverseMeter / ReciprocalArea.InverseSquareMeter",
-  "Length.Meter = RotationalStiffness.NewtonMeterPerRadian / RotationalStiffnessPerLength.NewtonMeterPerRadianPerMeter",
   "Length.Meter = Speed.MeterPerSecond * Duration.Second",
-  "Length.Meter = Torque.NewtonMeter / Force.Newton",
-  "Length.Meter = Volume.CubicMeter / Area.SquareMeter",
   "LinearDensity.KilogramPerMeter = Area.SquareMeter * Density.KilogramPerCubicMeter",
-  "LinearDensity.KilogramPerMeter = Mass.Kilogram / Length.Meter",
-  "Luminance.CandelaPerSquareMeter = LuminousIntensity.Candela / Area.SquareMeter",
   "LuminousIntensity.Candela = Luminance.CandelaPerSquareMeter * Area.SquareMeter",
   "Mass.Gram = AmountOfSubstance.Mole * MolarMass.GramPerMole",
   "Mass.Kilogram = AreaDensity.KilogramPerSquareMeter * Area.SquareMeter",
   "Mass.Kilogram = Density.KilogramPerCubicMeter * Volume.CubicMeter",
-  "Mass.Kilogram = Energy.Joule / SpecificEnergy.JoulePerKilogram",
-  "Mass.Kilogram = Force.Newton / Acceleration.MeterPerSecondSquared",
   "Mass.Kilogram = LinearDensity.KilogramPerMeter * Length.Meter",
-  "Mass.Kilogram = Mass.Kilogram / MassFraction.DecimalFraction",
-  "Mass.Kilogram = MassConcentration.KilogramPerCubicMeter * Volume.CubicMeter",
+  "Mass.Kilogram = MassConcentration.KilogramPerCubicMeter * Volume.CubicMeter -- NoInferredDivision",
   "Mass.Kilogram = MassFlow.KilogramPerSecond * Duration.Second",
   "Mass.Kilogram = MassFraction.DecimalFraction * Mass.Kilogram",
-  "MassConcentration.GramPerCubicMeter = Molarity.MolePerCubicMeter * MolarMass.GramPerMole",
+  "MassConcentration.KilogramPerCubicMeter = Molarity.MolePerCubicMeter * MolarMass.KilogramPerMole",
   "MassConcentration.KilogramPerCubicMeter = VolumeConcentration.DecimalFraction * Density.KilogramPerCubicMeter",
-  "MassFlow.GramPerSecond = Area.SquareMeter * MassFlux.GramPerSecondPerSquareMeter",
-  "MassFlow.KilogramPerSecond = Mass.Kilogram / Duration.Second",
+  "MassFlow.KilogramPerSecond = Area.SquareMeter * MassFlux.KilogramPerSecondPerSquareMeter",
   "MassFlow.KilogramPerSecond = MolarFlow.KilomolePerSecond * MolarMass.KilogramPerKilomole",
   "MassFlow.KilogramPerSecond = Power.Watt * BrakeSpecificFuelConsumption.KilogramPerJoule",
-  "MassFlow.KilogramPerSecond = Power.Watt / SpecificEnergy.JoulePerKilogram",
   "MassFlow.KilogramPerSecond = VolumeFlow.CubicMeterPerSecond * Density.KilogramPerCubicMeter",
-  "MassFlux.KilogramPerSecondPerSquareMeter = MassFlow.KilogramPerSecond / Area.SquareMeter",
   "MassFlux.KilogramPerSecondPerSquareMeter = Speed.MeterPerSecond * Density.KilogramPerCubicMeter",
-  "Molarity.MolePerCubicMeter = AmountOfSubstance.Mole / Volume.CubicMeter",
-  "Molarity.MolePerCubicMeter = MassConcentration.GramPerCubicMeter / MolarMass.GramPerMole",
+  "MolarFlow.MolePerSecond = VolumeFlow.CubicMeterPerSecond * Molarity.MolePerCubicMeter",
   "Molarity.MolePerCubicMeter = Molarity.MolePerCubicMeter * VolumeConcentration.DecimalFraction",
   "Power.Watt = ElectricPotential.Volt * ElectricCurrent.Ampere",
   "Power.Watt = Energy.Joule * Frequency.PerSecond",
-  "Power.Watt = Energy.Joule / Duration.Second",
   "Power.Watt = Force.Newton * Speed.MeterPerSecond",
   "Power.Watt = HeatFlux.WattPerSquareMeter * Area.SquareMeter",
-  "Power.Watt = MassFlow.KilogramPerSecond / BrakeSpecificFuelConsumption.KilogramPerJoule",
   "Power.Watt = SpecificEnergy.JoulePerKilogram * MassFlow.KilogramPerSecond",
+  "Power.Watt = Torque.NewtonMeter * RotationalSpeed.RadianPerSecond",
   "Pressure.NewtonPerSquareMeter = Force.Newton * ReciprocalArea.InverseSquareMeter",
   "Pressure.NewtonPerSquareMeter = ForcePerLength.NewtonPerMeter * ReciprocalLength.InverseMeter",
-  "Pressure.NewtonPerSquareMeter = ForcePerLength.NewtonPerMeter / Length.Meter",
-  "Pressure.Pascal = Force.Newton / Area.SquareMeter",
   "Pressure.Pascal = PressureChangeRate.PascalPerSecond * Duration.Second",
   "Pressure.Pascal = SpecificWeight.NewtonPerCubicMeter * Length.Meter",
-  "PressureChangeRate.PascalPerSecond = Pressure.Pascal / Duration.Second",
   "Ratio.DecimalFraction = Area.SquareMeter * ReciprocalArea.InverseSquareMeter",
-  "ReciprocalArea.InverseSquareMeter = 1 / Area.SquareMeter",
   "ReciprocalArea.InverseSquareMeter = ReciprocalLength.InverseMeter * ReciprocalLength.InverseMeter",
-  "ReciprocalLength.InverseMeter = 1 / Length.Meter",
-  "ReciprocalLength.InverseMeter = ReciprocalArea.InverseSquareMeter / ReciprocalLength.InverseMeter",
-  "RotationalSpeed.RadianPerSecond = Angle.Radian / Duration.Second",
-  "RotationalSpeed.RadianPerSecond = Power.Watt / Torque.NewtonMeter",
+  "ReciprocalLength.InverseMeter = Length.Meter * ReciprocalArea.InverseSquareMeter",
   "RotationalStiffness.NewtonMeterPerRadian = RotationalStiffnessPerLength.NewtonMeterPerRadianPerMeter * Length.Meter",
-  "RotationalStiffness.NewtonMeterPerRadian = Torque.NewtonMeter / Angle.Radian",
-  "RotationalStiffnessPerLength.NewtonMeterPerRadianPerMeter = RotationalStiffness.NewtonMeterPerRadian / Length.Meter",
-  "SpecificEnergy.JoulePerKilogram = double / BrakeSpecificFuelConsumption.KilogramPerJoule",
-  "SpecificEnergy.JoulePerKilogram = Energy.Joule / Mass.Kilogram",
-  "SpecificEnergy.JoulePerKilogram = Power.Watt / MassFlow.KilogramPerSecond",
   "SpecificEnergy.JoulePerKilogram = SpecificEntropy.JoulePerKilogramKelvin * TemperatureDelta.Kelvin",
   "SpecificEnergy.JoulePerKilogram = Speed.MeterPerSecond * Speed.MeterPerSecond",
-  "SpecificEntropy.JoulePerKilogramKelvin = Entropy.JoulePerKelvin / Mass.Kilogram",
-  "SpecificEntropy.JoulePerKilogramKelvin = SpecificEnergy.JoulePerKilogram / TemperatureDelta.Kelvin",
   "SpecificWeight.NewtonPerCubicMeter = Acceleration.MeterPerSecondSquared * Density.KilogramPerCubicMeter",
-  "SpecificWeight.NewtonPerCubicMeter = Pressure.Pascal / Length.Meter",
   "Speed.MeterPerSecond = Acceleration.MeterPerSecondSquared * Duration.Second",
-  "Speed.MeterPerSecond = KinematicViscosity.SquareMeterPerSecond / Length.Meter",
-  "Speed.MeterPerSecond = Length.Meter / Duration.Second",
-  "Speed.MeterPerSecond = MassFlux.KilogramPerSecondPerSquareMeter / Density.KilogramPerCubicMeter",
-  "Speed.MeterPerSecond = VolumeFlow.CubicMeterPerSecond / Area.SquareMeter",
   "TemperatureDelta.DegreeCelsius = TemperatureChangeRate.DegreeCelsiusPerSecond * Duration.Second",
   "TemperatureDelta.DegreeCelsius = TemperatureGradient.DegreeCelsiusPerKilometer * Length.Kilometer",
-  "TemperatureDelta.Kelvin = Energy.Joule / Entropy.JoulePerKelvin",
-  "TemperatureGradient.KelvinPerMeter = TemperatureDelta.Kelvin / Length.Meter",
   "Torque.NewtonMeter = ForcePerLength.NewtonPerMeter * Area.SquareMeter",
   "Torque.NewtonMeter = Length.Meter * Force.Newton",
-  "Torque.NewtonMeter = Power.Watt / RotationalSpeed.RadianPerSecond",
   "Torque.NewtonMeter = RotationalStiffness.NewtonMeterPerRadian * Angle.Radian",
-  "Volume.CubicMeter = AmountOfSubstance.Mole / Molarity.MolePerCubicMeter",
-  "Volume.CubicMeter = AreaMomentOfInertia.MeterToTheFourth / Length.Meter",
   "Volume.CubicMeter = Length.Meter * Area.SquareMeter",
-  "Volume.CubicMeter = Mass.Kilogram / Density.KilogramPerCubicMeter",
   "Volume.CubicMeter = SpecificVolume.CubicMeterPerKilogram * Mass.Kilogram",
   "Volume.CubicMeter = VolumeFlow.CubicMeterPerSecond * Duration.Second",
-  "VolumeConcentration.DecimalFraction = MassConcentration.KilogramPerCubicMeter / Density.KilogramPerCubicMeter",
-  "VolumeFlow.CubicMeterPerSecond = Area.SquareMeter * Speed.MeterPerSecond",
-  "VolumeFlow.CubicMeterPerSecond = MassFlow.KilogramPerSecond / Density.KilogramPerCubicMeter",
-  "VolumeFlow.CubicMeterPerSecond = MolarFlow.MolePerSecond / Molarity.MolePerCubicMeter",
-  "VolumeFlow.CubicMeterPerSecond = Volume.CubicMeter / Duration.Second"
+  "VolumeFlow.CubicMeterPerSecond = Area.SquareMeter * Speed.MeterPerSecond"
 ]

UnitsNet.Tests/CustomCode/VolumeTests.cs

@@ -151,8 +151,8 @@ public void VolumeDividedByDurationEqualsVolumeFlow()
         [Fact]
         public void VolumeDividedByVolumeFlowEqualsTimeSpan()
         {
-            TimeSpan timeSpan = Volume.FromCubicMeters(20) / VolumeFlow.FromCubicMetersPerSecond(2);
-            Assert.Equal(TimeSpan.FromSeconds(10), timeSpan);
+            Duration duration = Volume.FromCubicMeters(20) / VolumeFlow.FromCubicMetersPerSecond(2);
+            Assert.Equal(Duration.FromSeconds(10), duration);
         }
     }
 }