code: def register_rpc(self, address, rpc_id, func):
          
  
          if rpc_id < 0 or rpc_id > 0xFFFF:
              raise RPCInvalidIDError("Invalid RPC ID: {}".format(rpc_id))
  
          if address not in self._rpc_overlays:
              self._rpc_overlays[address] = RPCDispatcher()
  
          self._rpc_overlays[address].add_rpc(rpc_id, func)
docs: Register a single RPC handler with the given info.
  
          This function can be used to directly register individual RPCs,
          rather than delegating all RPCs at a given address to a virtual
          Tile.
  
          If calls to this function are mixed with calls to add_tile for
          the same address, these RPCs will take precedence over what is
          defined in the tiles.
  
          Args:
              address (int): The address of the mock tile this RPC is for
              rpc_id (int): The number of the RPC
              func (callable): The function that should be called to handle the
                  RPC.  func is called as func(payload) and must return a single
                  string object of up to 20 bytes with its response