code: def _try_validate(cnf, schema, **options):
      
      valid = True
      if schema:
          (valid, msg) = validate(cnf, schema, **options)
          if msg:
              LOGGER.warning(msg)
  
      if valid:
          return cnf
  
      return None
docs: :param cnf: Mapping object represents configuration data
      :param schema: JSON schema object
      :param options: Keyword options passed to :func:`jsonschema.validate`
  
      :return: Given 'cnf' as it is if validation succeeds else None