docs: def pick_by(self, func: Callable[[K, T], bool]) -> 'TDict[T]':
          """
          Usage:
  
              >>> TDict(k1=1, k2=2, k3=3).pick_by(lambda k, v: v > 2)
              {'k3': 3}
          """
          return TDict({k: v for k, v in self.items() if func(k, v)})