def METHOD_NAME(self, proj4):
    """
    Helper function that actually retrieves geojson from the
    database, combines into a geojson featurecollection, and
    sets a proj4 string on it.
    Parameters
    ----------
    proj4 : str
        Valid proj4 string to project to.
    Returns
    -------
    dict
    """
    features = [
        {"type": x[0], "id": x[1], "geometry": x[2], "properties": x[3]}
        for x in get_db().fetch(self.geojson_query(crs=proj4))
    ]
    js = {
        "properties": {"crs": proj4},
        "type": "FeatureCollection",
        "features": features,
    }
    return js