code: def test_merge_multiple(self):
      def split_info_for(
          name: str, shard_lengths, template
      ) -> splits.SplitInfo:
          return splits.SplitInfo(
              name=name,
              shard_lengths=shard_lengths,
              num_bytes=0,
              filename_template=template,
          )
  
      template_a = naming.ShardedFileTemplate(
          dataset_name="ds_name",
          data_dir="/a",
          filetype_suffix="tfrecord",
      )
      split_info_a1 = split_info_for("train", [1, 2, 3], template_a)
      split_info_a2 = split_info_for("test", [1], template_a)
      split_info_a3 = split_info_for("banana", [1], template_a)
      split_dict_1 = splits.SplitDict(
          [split_info_a1, split_info_a2, split_info_a3]
      )
  
      template_b = naming.ShardedFileTemplate(
          dataset_name="ds_name",
          data_dir="/b",
          filetype_suffix="tfrecord",
      )
      split_info_b1 = split_info_for("train", [4, 5, 6], template_b)
      split_info_b2 = split_info_for("test", [3], template_b)
      split_dict_2 = splits.SplitDict([split_info_b1, split_info_b2])
  
      template_c = naming.ShardedFileTemplate(
          dataset_name="ds_name",
          data_dir="/c",
          filetype_suffix="tfrecord",
      )
      split_info_c1 = split_info_for("train", [8], template_c)
      split_info_c2 = split_info_for("train", [9], template_c)
      multi_split = splits.MultiSplitInfo(
          name="train", split_infos=[split_info_c1, split_info_c2]
      )
      split_dict_3 = splits.SplitDict([multi_split])
  
      merged = splits.SplitDict.merge_multiple(
          [split_dict_1, split_dict_2, split_dict_3]
      )
      assert len(merged.values()) == 3
      assert merged.get("train").split_infos == [
          split_info_a1,
          split_info_b1,
          split_info_c1,
          split_info_c2,
      ]
      assert merged.get("test").split_infos == [
          split_info_a2,
          split_info_b2,
      ]
      assert merged.get("banana").split_infos == [split_info_a3]
  
imports: from tensorflow_datasets import testing
  from tensorflow_datasets.core import naming
  from tensorflow_datasets.core import proto
  from tensorflow_datasets.core import splits
  from tensorflow_datasets.core.utils import shard_utils
  import tensorflow_datasets.public_api
label_desc: Use image node_id 8 for calling the SplitDictTest obj's underlying member method code with example usage: obj.test_merge_multiple() and returns: splits