How to create geometry from relation?

I tried to get geometries from relations but I was getting ArgumentError for both .create_linestring() and .create_multipolygon(). I also tried both methods for each r.memberelement but with the same error. Both area and way geometries are working. Here is a snippet of my code:

import osmium as osm
import shapely.wkb

wkb_factory = osm.geom.WKBFactory()

class OSMHandler(osm.SimpleHandler):
    def __init__(self):
        osm.SimpleHandler.__init__(self)
        self.amenities = []

    def relation(self, r):        
        if 'amenity' in r.tags:
            wkb = wkb_factory.create_linestring(r)
            multipolygon = shapely.wkb.loads(wkb, hex=True)
            lon, lat = line.centroid.x, line.centroid.y
            
            self.amenities.append([r.id, r.tags['amenity'], lon, lat])
                
handler = OSMHandler()
handler.apply_file('liechtenstein-latest.osm.pbf', locations=True)

ArgumentError: Python argument types in
WKBFactory.create_multipolygon(WKBFactory, Relation)
did not match C++ signature:
create_multipolygon(WKBFactory {lvalue} self, osmium::Area area)

Is there a proper way to get the geometry from a relation in pyosmium? Thank you in advance.

[aginpatrick]

@njanakiev Did you find a way to solve your problem ? I need the same to build a multi-linestring from relation

[njanakiev]

Thank you for clarification, @lonvia