'List distinct values for a given field from the library.
:param string field: One of ``artist``, ``albumartist``, ``album``,
``composer``, ``performer``, ``date``or ``genre``.
:param dict query: Query to use for limiting results, see
:meth:`search` for details about the query format.
:rtype: set of values corresponding to the requested field type.'

def get_distinct(self, field, query=None):

    return set()
