class_docstr: Test some basic splitters.
docstr: Test singletask IndexSplitter class.
code: def test_singletask_index_split(self):
      """
      Test singletask IndexSplitter class.
      """
      solubility_dataset = load_solubility_data()
      random_splitter = dc.splits.IndexSplitter()
      (
          train_data,
          valid_data,
          test_data,
      ) = random_splitter.train_valid_test_split(solubility_dataset)
      assert len(train_data) == 8
      assert len(valid_data) == 1
      assert len(test_data) == 1
  
      merged_dataset = dc.data.DiskDataset.merge(
          [train_data, valid_data, test_data]
      )
      assert sorted(merged_dataset.ids) == (
          sorted(solubility_dataset.ids)
      )
  
imports: import os
  import unittest
  import numpy
  import deepchem
  from deepchem.data import NumpyDataset
  from deepchem.splits import IndexSplitter
label_desc: Use image node_id 3 for calling the TestSplitter obj's underlying member method code with example usage: obj.test_singletask_index_split() without return types