createValidSetValueTestCallback = (testCase) => {
    return function () {
      this.field.setValue(testCase.value);
      assertFieldValue(
        this.field,
        testCase.expectedValue,
        testCase.expectedText,
      );
    };
  }
Creates test callback for valid setValue test.
@param {!FieldValueTestCase} testCase The test case information.
@returns {!Function} The test callback.