Memory leak in mongoDB

#%%

import gc

from typing import Any

from pymongo import MongoClient

from bson.codec_options import CodecOptions

from bson.codec_options import TypeCodec, TypeRegistry

#%% Define method to analyse the memory

def memory_report():

    gc.collect()

    rr={}

    for obj in gc.get_objects():

        tt=type(obj)

        if 'bson' in str(tt):

            rr[tt] = rr.get(tt, 0)+1

    print('memory report:')

    for key in rr:

        nn=rr[key]

        print(f' {key}: {nn}')

#%% Create codec

class MyClass:

    pass

class MyCodec(TypeCodec):  # type: ignore

    pass

    @property

    def python_type(self) -> Any:

         return MyClass

    def transform_python(self, value: Any) -> Any:

        #print(f'transform_python: {value}')

        return value

    @property

    def bson_type(self) -> Any:

         return dict

    def transform_bson(self, value: Any) -> Any:

         #print(f'transform_bson: {value}')

         return value

codec=MyCodec()

type_registry = TypeRegistry([codec]) 

codec_options = CodecOptions(type_registry=type_registry) 

client = MongoClient('localhost:27017')

database = client['my_database']

collection = database['my_collection'].with_options(codec_options)

for ii in range(3000):

    cursor = collection.find({})

    for data in cursor:

        pass

_=memory_report() # for multiple iterations objects of type bson.codec_options.CodecOptions are leaking