code: def add(self, operator, *args):
          
  
          if isinstance(operator, str):
              op = getattr(proxops, operator)(*args)
          elif isinstance(operator, proxops.ProximalOperatorBaseClass):
              op = operator
          else:
              raise ValueError("operator must be a string or a subclass of ProximalOperator")
  
          self.operators.append(op)
          return self
docs: Adds a proximal operator to the list of operators