code: def remove(self, *args):
          '''
          cplan.remove(...) yields a new calculation plan identical to cplan except without any of
          the calculation steps listed in the arguments. An exception is raised if any keys are not
          found in the calc-plan.
          '''
          return Plan(reduce(lambda m,k: m.remove(k), args, self.nodes)f remove(self, *args):
          '''
          cplan.remove(...) yields a new calculation plan identical to cplan except without any of
          the calculation steps listed in the arguments. An exception is raised if any keys are not
          found in the calc-plan.
          '''
          return Plan(reduce(lambda m,k: m.remove(k), args, self.nodes))
docs: cplan.remove(...) yields a new calculation plan identical to cplan except without any of
          the calculation steps listed in the arguments. An exception is raised if any keys are not
          found in the calc-plan.