Retrieve the scripts from attribute metadata.

    Args:
      attribute_data: dict, the contents of the attributes metadata.
      dest_dir: string, the path to a directory for storing metadata scripts.

    Returns:
      dict, a dictionary mapping metadata keys to files storing scripts.

def _GetAttributeScripts(self, attribute_data, dest_dir):
    """Retrieve the scripts from attribute metadata.

    Args:
      attribute_data: dict, the contents of the attributes metadata.
      dest_dir: string, the path to a directory for storing metadata scripts.

    Returns:
      dict, a dictionary mapping metadata keys to files storing scripts.
    """
    script_dict = {}
    attribute_data = attribute_data or {}
    metadata_key = '%s-script' % self.script_type
    metadata_value = attribute_data.get(metadata_key)
    if metadata_value:
      self.logger.info('Found %s in metadata.', metadata_key)
      with tempfile.NamedTemporaryFile(
          mode='w', dir=dest_dir, delete=False) as dest:
        dest.write(metadata_value.lstrip())
        script_dict[metadata_key] = dest.name

    metadata_key = '%s-script-url' % self.script_type
    metadata_value = attribute_data.get(metadata_key)
    if metadata_value:
      self.logger.info('Found %s in metadata.', metadata_key)
      script_dict[metadata_key] = self._DownloadScript(
          metadata_value, dest_dir)

    return script_dict