code: def _is_power_of_2(n):
      if (not isinstance(n, int)) or (n < 0):
          raise ValueError(
              "invalid input for _is_power_of_2: {} (type: {})".format(
                  n, type(n)
              )
          )
      return (n & (n - 1) == 0) and n != 0
  
file_path: PaddleSeg/paddleseg/models/layers/ms_deformable_attention.py
imports: import math
  import warnings
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.cvlibs import param_init
  from paddleseg.cvlibs.param_init import constant_init, xavier_uniform
label_desc: Use image node_id 2 for calling the MSDeformAttn obj's underlying member method code with example usage: obj._is_power_of_2(n) and returns: unknown