code: def create(cls, request_bytes, monetary_account_id=None,
                 custom_headers=None):
          
  
          if custom_headers is None:
              custom_headers = {}
  
          api_client = client.ApiClient(cls._get_api_context())
          endpoint_url = cls._ENDPOINT_URL_CREATE.format(cls._determine_user_id(),
                                                         cls._determine_monetary_account_id(
                                                             monetary_account_id))
          response_raw = api_client.post(endpoint_url, request_bytes,
                                         custom_headers)
  
          return BunqResponseInt.cast_from_bunq_response(
              cls._process_for_id(response_raw)
          )
docs: Create a new monetary account attachment. Create a POST request with a
          payload that contains the binary representation of the file, without any
          JSON wrapping. Make sure you define the MIME type (i.e. image/jpeg) in
          the Content-Type header. You are required to provide a description of
          the attachment using the X-Bunq-Attachment-Description header.
  
          :type user_id: int
          :type monetary_account_id: int
          :type custom_headers: dict[str, str]|None
  
          :rtype: BunqResponseInt