code: def set_func(self, name, func):
          
  
          self.func_name = name
          self.func = func
docs: Set the processing function to use for this node.
  
          Args:
              name (str): The name of the function to use.  This is
                  just stored for reference in case we need to serialize
                  the node later.
              func (callable): A function that is called to process inputs
                  for this node.  It should have the following signature:
                  callable(input1_walker, input2_walker, ...)
                  It should return a list of IOTileReadings that are then pushed into
                  the node's output stream