code: def __to_keras_shape(cls, shape):
      if shape[0] == -1:
          return tuple([None] + shape[1:])
      else:
          return tuple(shape)
  
imports: from bigdl.nn.layer import Layer
  from bigdl.util.common import *
  from zoo.common.utils import callZooFunc
label_desc: Use image node_id 2 for calling the InferShape obj's underlying member method code with example usage: obj.__to_keras_shape(cls, shape) and returns: tuple, tuple