@staticmethod
def _get_item(list_containing_dicts_entries, attribute_value,
    attribute_name='subnet_id'):
    """Searches a list of dicts and returns the first matching entry

        The dict entry returned contains the attribute 'attribute_name' whose
        value equals 'attribute_value'. If no such dict is found in the list
        an empty dict is returned.
        """
    for item in list_containing_dicts_entries:
        if item.get(attribute_name) == attribute_value:
            return item
    return {}
