code: def is_memoized(self, k):
          '''
          lmap.is_memoized(k) yields True if k is a key in the given lazy map lmap that is both lazy
          and already memoized.
          '''
          v = ps.PMap.__getitem__(self, k)
          if not isinstance(v, (types.FunctionType, partial)):
              return False
          else:
              return id(v) in self._memoizef is_memoized(self, k):
          '''
          lmap.is_memoized(k) yields True if k is a key in the given lazy map lmap that is both lazy
          and already memoized.
          '''
          v = ps.PMap.__getitem__(self, k)
          if not isinstance(v, (types.FunctionType, partial)):
              return False
          else:
              return id(v) in self._memoized
docs: lmap.is_memoized(k) yields True if k is a key in the given lazy map lmap that is both lazy
          and already memoized.