code: def __call__(self, *inputs):
      outputs = []
      idx = None
      for idx, _input in enumerate(inputs):
          _input_dst = (
              _input[0] * 0.299 + _input[1] * 0.587 + _input[2] * 0.114
          )
          _input_gs = _input_dst.repeat(self.channels, 1, 1)
          outputs.append(_input_gs)
      return outputs if idx >= 1 else outputs[0]
  
imports: import random
  import torch
  from torchvision.transforms.functional import to_tensor
  import numpy
  from ..utils import th_random_choice
label_desc: Use image node_id 2 for calling the Grayscale obj's underlying member method code with example usage: obj.__call__() and returns: unknown