code: def get_csig(self, calc=None):
          
          try:
              return self.ninfo.csig
          except AttributeError:
              pass
          contents = self.get_contents()
          self.get_ninfo().csig = contents
          return contents
docs: Because we're a Python value node and don't have a real
          timestamp, we get to ignore the calculator and just use the
          value contents.