@Test
 public void testInvalidParameterName() {
   final FormValidation validation = testValidator.validateParameterName("123param");
   assertEquals(
       "Invalid parameter name starts with non-letter char",
       FormValidation.Kind.ERROR,
       validation.kind);
 }
 @Test
 public void testParameterizedParameterName() {
   final FormValidation validation = testValidator.validateParameterName("${PARAM}");
   assertEquals(
       "Warning if parameterized parameter name", FormValidation.Kind.WARNING, validation.kind);
 }
 @Test
 public void testValidParameterName() {
   final FormValidation validation = testValidator.validateParameterName("param_123");
   assertEquals(
       "Valid parameter name starts with a letter char", FormValidation.Kind.OK, validation.kind);
 }
 @Test
 public void testNullParameterName() {
   final FormValidation validation = testValidator.validateParameterName(null);
   assertEquals("Error if empty parameter name", FormValidation.Kind.ERROR, validation.kind);
 }