code: def update_buffer_with_value( self, value, buffer, parent=None ):
          
          assert common.is_bytes( buffer )
          self.validate( value, parent )
          return
docs: Write a Python object into a byte array, using the field definition.
  
          value
              Input Python object to process.
  
          buffer
              Output byte array to encode value into.
  
          parent
              Parent block object where this Field is defined. Used for e.g.
              evaluating Refs.