'Creates an index if it doesn\'t already exist.
If supplied, settings must be a dictionary.
:param index: the name of the index
:keyword settings: a settings object or a dict containing settings'

def create_index_if_missing(self, index, settings=None):

    try:
        return self.create_index(index, settings)
    except IndexAlreadyExistsException as e:
        return e.result
