docs: def label(self):
          """"Return first child of the column that is marked as a label. Returns self if the column is a label"""
  
          if self.valuetype_class.is_label():
              return self
  
          for c in self.table.columns:
              if c.parent == self.name and  c.valuetype_class.is_label():
                  return c
  
          return None