How to use the wradlib.georef.vector function in wradlib

def _get_data(self):
        """ Returns DataSource geometries as numpy ndarrays
        """
        lyr = self.ds.GetLayer()
        sources = []
        for feature in lyr:
            geom = feature.GetGeometryRef()
            poly = georef.vector.ogr_to_numpy(geom)
            sources.append(poly)
        return np.array(sources)

lyr = self.trg.ds.GetLayerByName('trg')
                    feat = lyr.GetFeature(idx)
                    trg = feat.GetGeometryRef()
                except Exception:
                    raise TypeError("No target polygon found at index {0}".
                                    format(idx))
            else:
                raise TypeError('No target polygons found in object!')

        # check for trg
        if trg is None:
            raise TypeError('Either *trg* or *idx* keywords must be given!')

        # check for geometry
        if not type(trg) == ogr.Geometry:
            trg = georef.vector.numpy_to_ogr(trg, 'Polygon')

        # apply Buffer value
        trg = trg.Buffer(buf)

        if idx is None:
            intersecs = self.dst.get_data_by_geom(trg)
        else:
            intersecs = self.dst.get_data_by_att('trg_index', idx)

        return intersecs

tmpfile = tempfile.NamedTemporaryFile(mode='w+b').name
        ogr_src = io.gdal.gdal_create_dataset('ESRI Shapefile',
                                              os.path.join('/vsimem', tmpfile),
                                              gdal_type=gdal.OF_VECTOR)

        src = np.array(src)
        # create memory datasource, layer and create features
        if src.ndim == 2:
            geom_type = ogr.wkbPoint
        # no Polygons, just Points
        else:
            geom_type = ogr.wkbPolygon
        fields = [('index', ogr.OFTInteger)]
        georef.vector.ogr_create_layer(ogr_src, self._name, srs=self._srs,
                                       geom_type=geom_type, fields=fields)
        georef.vector.ogr_add_feature(ogr_src, src, name=self._name)

        return ogr_src

trg_lyr.ResetReading()
        trg_lyr.SetSpatialFilter(None)

        # buffer handling (time consuming)
        if self._buffer > 0:
            for i in range(trg_lyr.GetFeatureCount()):
                feat = trg_lyr.GetFeature(i)
                feat.SetGeometryDirectly(feat.GetGeometryRef().
                                         Buffer(self._buffer))
                trg_lyr.SetFeature(feat)

        # reset target layer
        trg_lyr.ResetReading()

        # create tmp dest layer
        self.tmp_lyr = georef.vector.ogr_create_layer(ds_mem, 'dst',
                                                      srs=self._srs,
                                                      geom_type=geom_type)

        trg_lyr.Intersection(src_lyr, self.tmp_lyr,
                             options=['SKIP_FAILURES=YES',
                                      'INPUT_PREFIX=trg_',
                                      'METHOD_PREFIX=src_',
                                      'PROMOTE_TO_MULTI=YES',
                                      'USE_PREPARED_GEOMETRIES=YES',
                                      'PRETEST_CONTAINMENT=YES'],
                             callback=progress)

        georef.vector.ogr_copy_layer(ds_mem, 0, ds_out)

        return ds_out

# create tmp dest layer
        self.tmp_lyr = georef.vector.ogr_create_layer(ds_mem, 'dst',
                                                      srs=self._srs,
                                                      geom_type=geom_type)

        trg_lyr.Intersection(src_lyr, self.tmp_lyr,
                             options=['SKIP_FAILURES=YES',
                                      'INPUT_PREFIX=trg_',
                                      'METHOD_PREFIX=src_',
                                      'PROMOTE_TO_MULTI=YES',
                                      'USE_PREPARED_GEOMETRIES=YES',
                                      'PRETEST_CONTAINMENT=YES'],
                             callback=progress)

        georef.vector.ogr_copy_layer(ds_mem, 0, ds_out)

        return ds_out