def get_unspent_outputs(connection, *, query=None):
    """Retrieves unspent outputs.

    Args:
        query (dict): An optional parameter to filter the result set.
            Defaults to ``None``, which means that all UTXO records
            will be returned.

    Returns:
        Generator yielding unspent outputs (UTXO set) according to the
        given query.
    """

    raise NotImplementedError
Retrieves unspent outputs.

Args:
query (dict): An optional parameter to filter the result set.
Defaults to ``None``, which means that all UTXO records
will be returned.

Returns:
Generator yielding unspent outputs (UTXO set) according to the
given query.
bigchaindb/backend/query.py