def METHOD_NAME(self, mp_get_schema,
                                   mp_remote_describefeaturetype,
                                   mp_remote_wfs_feature, mp_dov_xml):
    """Test the search method with custom return fields.
    Test whether the output dataframe is correct.
    Parameters
    ----------
    mp_get_schema : pytest.fixture
        Monkeypatch the call to a remote OWSLib schema.
    mp_remote_describefeaturetype : pytest.fixture
        Monkeypatch the call to a remote DescribeFeatureType .
    mp_remote_wfs_feature : pytest.fixture
        Monkeypatch the call to get WFS features.
    mp_dov_xml : pytest.fixture
        Monkeypatch the call to get the remote XML data.
    """
    df = self.search_instance.search(
        query=self.valid_query_single,
        return_fields=('pkey_interpretatie', 'pkey_boring',
                       'pkey_sondering'))
    assert isinstance(df, DataFrame)
    assert list(df) == ['pkey_interpretatie', 'pkey_boring',
                        'pkey_sondering']
    assert not pd.isnull(df.pkey_boring[0])
    assert np.isnan(df.pkey_sondering[0])