text: import unittest
  
  import numpy as np
  import tensorflow as tf
  import torch
  
  import fastestimator as fe
  from fastestimator.test.unittest_util import is_equal
  
  
  class TestGatherFromBatch(unittest.TestCase):
      def test_gather_from_batch_np_input(self):
          tensor = np.array([[0, 1], [2, 3], [4, 5]])
          indice = np.array([1, 0, 1])
          obj1 = fe.backend.gather_from_batch(tensor, indice)
          obj2 = np.array([1, 2, 5])
          self.assertTrue(is_equal(obj1, obj2))
  
      def test_gather_from_batch_tf_input(self):
          tensor = tf.constant([[0, 1], [2, 3], [4, 5]])
          indice = tf.constant([1, 0, 1])
          obj1 = fe.backend.gather_from_batch(tensor, indice)
          obj2 = tf.constant([1, 2, 5])
          self.assertTrue(is_equal(obj1, obj2))
  
          tensor = tf.constant([[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]]])
          obj1 = fe.backend.gather_from_batch(tensor, indice)
          obj2 = tf.constant([[2, 3], [4, 5], [10, 11]])
          self.assertTrue(is_equal(obj1, obj2))
  
      def test_gather_from_batch_torch_input_2D(self):
          tensor = torch.tensor([[0, 1], [2, 3], [4, 5]])
          indice = torch.tensor([1, 0, 1])
          obj1 = fe.backend.gather_from_batch(tensor, indice)
          obj2 = torch.tensor([1, 2, 5])
          self.assertTrue(is_equal(obj1, obj2))
  
      def test_gather_from_batch_torch_input_3D(self):
          tensor = torch.tensor([[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]]])
          indice = torch.tensor([1, 0, 1])
          obj1 = fe.backend.gather_from_batch(tensor, indice)
          obj2 = torch.tensor([[2, 3], [4, 5], [10, 11]])
          self.assertTrue(is_equal(obj1, obj2))
  
      def test_gather_from_batch_input_and_indice_diff_type_2D(self):
          tensor = torch.tensor([[0, 1], [2, 3], [4, 5]])
          indice = np.array([1, 0, 1])
          obj1 = fe.backend.gather_from_batch(tensor, indice)
          obj2 = torch.tensor([1, 2, 5])
          self.assertTrue(is_equal(obj1, obj2))
  
      def test_gather_from_batch_input_and_indice_diff_type_3D(self):
          tensor = tf.constant([[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]]])
          indice = torch.tensor([1, 0, 1])
          obj1 = fe.backend.gather_from_batch(tensor, indice)
          obj2 = tf.constant([[2, 3], [4, 5], [10, 11]])
          self.assertTrue(is_equal(obj1, obj2))
  