comefrom: <doocs>0089.Gray Code_1.py
code: def grayCode( n: int) -> List[int]:
      return [i ^ (i >> 1) for i in range(1 << n)]
masked: def sample_funcname ( var_0 : int ) -> List [ int ] :
      return [ var_3 ^ ( var_3 >> 1 ) for var_3 in range ( 1 << var_0 ) ]
  