docs: def bind_to(self, table, name):
          """
          Bind this column to a table, and assign it a name. This method
          can only be called once per instance, because a Column cannot be
          bound to multiple tables. (The sort order would be ambiguous.)
          """
          if self.bound_to is not None:
              raise AttributeError(
                  "Column is already bound to '%s' as '%s'" %\
                      self.bound_to)
  
          self.bound_to = (table, name)