'Add an alias to point to a set of indices.
(See :ref:`es-guide-reference-api-admin-indices-aliases`)
:param alias: the name of an alias
:param indices: a list of indices'

def add_alias(self, alias, indices, **kwargs):

    indices = self.conn._validate_indices(indices)
    return self.change_aliases((['add', index, alias, self._get_alias_params(**kwargs)] for index in indices))
