docstr: test for normal search space
          
docstr_tok: ["test","for","normal","search","space"]
code: def test_split_index_normal(self):
      """test for normal search space"""
      normal__params_with_index = {
          "dropout_rate": {"_index": 1, "_value": 0.9},
          "hidden_size": {"_index": 1, "_value": 512},
      }
      normal__params = {"dropout_rate": 0.9, "hidden_size": 512}
  
      params = split_index(normal__params_with_index)
      self.assertEqual(params, normal__params)
  
imports: from unittest import TestCase, main
  import nni
  from nni.utils import split_index
label_desc: Use image node_id 1 for calling the UtilsTestCase obj's underlying member method code with example usage: obj.test_split_index_normal() without return types