code: def assign_group_v2(group_assignment, device_index, base_key):
      """Assign group key based on group_assignment.
  
      Args:
        group_assignment: a 2 dimensional integer Tensor that encodes which devices
          belong to the same group. The values are indices of the devices within 0
          to number of devices.
        device_index: integer for the index of the current device
        base_key: integer to offset the resulted group_key. The base key shall be
          unique for different values of group_assignment in the same tf.function.
      Notes: The device_index argument must be consistent with the index of the
        device of this Op in the device assignment list. The behavior of this Op is
        undefined if they are inconsistent.
  
      Returns:
        group_size, group_key: The group size and group key for the current device.
      """
      (
          group_size,
          group_key,
      ) = gen_collective_ops.collective_assign_group_v2(
          group_assignment=group_assignment,
          device_index=device_index,
          base_key=base_key,
      )
      return group_size, group_key
  
file_path: tensorflow/tensorflow/python/ops/collective_ops.py
imports: from tensorflow.python.ops import gen_collective_ops
label_desc: Use image node_id 2 for calling a global function with example usage: assign_group_v2(group_assignment, device_index, base_key) and returns: group_size,  group_key