class_docstr: Testing the DATA_LIMIT underlying sub sampling methods
code: def test_unbalanced_sub_sampling(self) -> None:
      labels = np.array([0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 0])
  
      indices1 = unbalanced_sub_sampling(
          len(labels), num_samples=8, skip_samples=0
      )
      self.assertEqual(8, len(indices1))
      self.assertEqual(
          len(indices1), len(set(indices1)), "indices must be unique"
      )
  
      indices2 = unbalanced_sub_sampling(
          len(labels), num_samples=8, skip_samples=2
      )
      self.assertEqual(8, len(indices2))
      self.assertEqual(
          len(indices2), len(set(indices2)), "indices must be unique"
      )
  
      self.assertTrue(
          np.array_equal(indices1[2:], indices2[:-2]),
          "skipping samples should slide the window",
      )
  
imports: import unittest
  import numpy
  from vissl.data.data_helper import balanced_sub_sampling, unbalanced_sub_sampling
label_desc: Use image node_id 1 for calling the TestDataLimitSubSampling obj's underlying member method code with example usage: obj.test_unbalanced_sub_sampling() without return types