old_contents: from typing import Optional, Dict, Any
  
  from flask import request
  
  RequestData = Dict[str, Any]
  
  
  class BaseReceiver:
      def __init__(self):
          """This is the base model for all the models.
  
          used to handle requests and other common stuff
          """
          pass
  
      @property
      def _front_end_data_nullable(self) -> Optional[dict]:
          """An nullable front-end data
  
          the front end data, possibly None:
          - if not in an request context, you will get None
          - if no request data is sent in current request, you will get None
          :return: the front end data, possibly None.
          """
          try:
              return self._get_all_options_from_front_end()
          except RuntimeError:  # working out of request context
              return None
  
      @property
      def _front_end_data(self) -> RequestData:
          """The null-safe version of front end data.
  
          :return: all the front end data pack in a dict
          """
          assert self._front_end_data_nullable is not None
          return self._front_end_data_nullable
  
      @staticmethod
      def _get_all_options_from_front_end() -> Optional[RequestData]:
          """Get all the options from front end.
  
          This function is not null-safe:
          (which means this function is possible to return a none).
          :return: a optional dict with data from front end
          """
          if request.json:
              return dict(request.json)
          elif request.form:
              return dict(request.form)
          else:
              return None
  
      def options_from_front_end(self):
          """A virtual method to pack the specific option needed.
  
          find all the option needed and pack them into a struct.
          Needs to be implemented in other receivers
          """
          raise NotImplementedError
  
  
new_contents: from typing import Optional, Dict, Any
  
  from flask import request
  
  RequestData = Dict[str, Any]
  
  
  class BaseReceiver:
      def __init__(self):
          """This is the base model for all the models.
  
          used to handle requests and other common stuff
          """
          pass
  
      @property
      def _front_end_data_nullable(self) -> Optional[dict]:
          """An nullable front-end data
  
          the front end data, possibly None:
          - if not in an request context, you will get None
          - if no request data is sent in current request, you will get None
          :return: the front end data, possibly None.
          """
          try:
              return self._get_all_options_from_front_end()
          except RuntimeError:  # working out of request context
              return None
  
      @property
      def _front_end_data(self) -> RequestData:
          """The null-safe version of front end data.
  
          :return: all the front end data pack in a dict
          """
          assert self._front_end_data_nullable is not None
          return self._front_end_data_nullable
  
      @staticmethod
      def _get_all_options_from_front_end() -> Optional[RequestData]:
          """Get all the options from front end.
  
          This function is not null-safe:
          (which means this function is possible to return a none).
          :return: a optional dict with data from front end
          """
          if request.json:
              return dict(request.json)
          elif request.form:
              return dict(request.form)
          else:
              return None
  
      def options_from_front_end(self):
          """A virtual method to pack the specific option needed.
  
          find all the option needed and pack them into a struct.
          Needs to be implemented in other receivers
          """
          raise NotImplementedError
  
subject: remove blank line