Is this a valid policy template dictionary

        :param dict policy_templates_dict: Data to be validated
        :param dict schema: Optional, dictionary containing JSON Schema representing policy template
        :return: True, if it is valid.
        :raises ValueError: If the template dictionary doesn't match up with the schema

def _is_valid_templates_dict(policy_templates_dict, schema=None):
        """
        Is this a valid policy template dictionary

        :param dict policy_templates_dict: Data to be validated
        :param dict schema: Optional, dictionary containing JSON Schema representing policy template
        :return: True, if it is valid.
        :raises ValueError: If the template dictionary doesn't match up with the schema
        """

        if not schema:
            schema = PolicyTemplatesProcessor._read_schema()

        try:
            jsonschema.validate(policy_templates_dict, schema)
        except ValidationError as ex:
            # Stringifying the exception will give us useful error message
            raise ValueError(str(ex))

        return True