code: def load_constants(self):
          
  
          for stream, value in self.constant_database.items():
              self.sensor_log.push(stream, IOTileReading(0, stream.encode(), value))
docs: Load all constants into their respective streams.
  
          All previous calls to add_constant stored a constant value that
          should be associated with virtual stream walkers.  This function
          actually calls push_stream in order to push all of the constant
          values to their walkers.