fix test to use IsoDatetimeRange's own methods

Author: hkong-mitre

src/common/IsoDate/IsoDatetimeRange.test.unit.ts

@@ -2,7 +2,6 @@ import { describe, it, test, expect } from '@jest/globals';
 import { IsoDate, isValidIsoDate } from './IsoDate.js';
 import { IsoDatetime, toIsoDatetime, isIsoDatetime } from './IsoDatetime.js';
 import { IsoDatetimeRange, isIsoDatetimeRange } from './IsoDatetimeRange.js';
-import { SearchRequest } from '../../search/SearchRequest.js';
 
 describe('IsoDatetimeRange.parse (in depth)', () => {
   test('parses year‑only range', () => {
@@ -127,12 +126,12 @@ describe('IsoDatetimeRange.parse(), toString(), isIsoDatetimeRange()', () => {
           expect(range.toString()).toEqual(expected);
         }
         if (isDate) {
-          expect(SearchRequest.isDateString(input as string)).toBeTruthy();
-          expect(SearchRequest.isIsoDatetimeRange(input as string)).toBeFalsy();
+          expect(isValidIsoDate(input as string)).toBeTruthy();
+          expect(isIsoDatetimeRange(input as string)).toBeFalsy();
         }
         if (isDateRange) {
-          expect(SearchRequest.isDateString(input as string)).toBeFalsy();
-          expect(SearchRequest.isIsoDatetimeRange(input as string)).toBeTruthy();
+          expect(isValidIsoDate(input as string)).toBeFalsy();
+          expect(isIsoDatetimeRange(input as string)).toBeTruthy();
         }
       }
     });