code: def unwrap(self, d, item):
          
          nopt = ( lambda x: x )
          try:
              md = d.__metadata__
              pmd = getattr(md, '__print__', None)
              if pmd is None:
                  return item
              wrappers = getattr(pmd, 'wrappers', {})
              fn = wrappers.get(item[0], nopt)
              return (item[0], fn(item[1]))
          except:
              pass
          return item
docs: translate (unwrap) using an optional wrapper function