code: def get_size( self ):
          
          klass = self.__class__
          size = 0
          for name in klass._fields:
              size = max( size, klass._fields[name].get_end_offset( self._field_data[name], parent=self ) )
          for check in klass._checks.values():
              size = max( size, check.get_end_offset( parent=self ) )
          return size
docs: Get the projected size (in bytes) of the exported data from this Block instance.