docs: def validate_swagger_schema(schema_dir, resource_listing):
      """Validate the structure of Swagger schemas against the spec.
  
      **Valid only for Swagger v1.2 spec**
  
      Note: It is possible that resource_listing is not present in
      the schema_dir. The path is passed in the call so that ssv
      can fetch the api-declaration files from the path.
  
      :param resource_listing: Swagger Spec v1.2 resource listing
      :type resource_listing: dict
      :param schema_dir: A path to Swagger spec directory
      :type schema_dir: string
      :raises: :py:class:`swagger_spec_validator.SwaggerValidationError`
      """
      schema_filepath = os.path.join(schema_dir, API_DOCS_FILENAME)
      swagger_spec_validator.validator12.validate_spec(
          resource_listing,
          urlparse.urljoin('file:', pathname2url(os.path.abspath(schema_filepath))),
      )