Implement api_version on the legacy wrapper classes for contrib.solver and appsi

Author: sadavis1

pyomo/contrib/appsi/base.py

@@ -1686,6 +1686,18 @@ def __enter__(self):
     def __exit__(self, t, v, traceback):
         pass
 
+    @classmethod
+    def api_version(self):
+        """
+        Return the public API supported by this interface.
+
+        Returns
+        -------
+        ~pyomo.common.enums.SolverAPIVersion
+            A solver API enum object
+        """
+        return SolverAPIVersion.V1
+
 
 class SolverFactoryClass(Factory):
     def register(self, name, doc=None):

pyomo/contrib/solver/common/base.py

@@ -744,3 +744,15 @@ def warm_start_capable(self):
 
     def default_variable_value(self):
         return None
+
+    @classmethod
+    def api_version(self):
+        """
+        Return the public API supported by this interface.
+
+        Returns
+        -------
+        ~pyomo.common.enums.SolverAPIVersion
+            A solver API enum object
+        """
+        return SolverAPIVersion.V1