'Render a single tile, return a VectorResponse instance.'

def renderTile(self, width, height, srs, coord):

    (layer, ds) = _open_layer(self.driver, self.parameters, self.layer.config.dirpath)
    features = _get_features(coord, self.properties, self.layer.projection, layer, self.clipped, self.projected, self.spacing, self.id_property, self.skip_empty_fields)
    response = {'type': 'FeatureCollection', 'features': features}
    if self.projected:
        sref = osr.SpatialReference()
        sref.ImportFromProj4(self.layer.projection.srs)
        response['crs'] = {'wkt': sref.ExportToWkt()}
        if (srs == getProjectionByName('spherical    mercator').srs):
            response['crs']['wkid'] = 102113
    else:
        response['crs'] = {'srid': 4326, 'wkid': 4326}
    return VectorResponse(response, self.verbose, self.precision)
