code: def delete(self):
          
          if self.parent is None:
              raise RuntimeError(
                  "Current statement has no parent, so it cannot "
                  + "be deleted form a procmailrc structure"
              )
          elif self.id is None:
              raise RuntimeError("id not set but have a parent, this should not be happening")
          else:
              parent_id = self.parent.id
              index = int(self.id.split('.')[-1])
              self.parent.pop(index)
              self.parent = None
              self.id = None
              return parent_id
docs: Remove the statement from a ProcmailRC structure, raise a
          RuntimeError if the statement is not inside a ProcmailRC structure
          return the parent id