code: def testOverlappingJobMergedClusterResolver(self):
      cluster_spec_1 = server_lib.ClusterSpec(
          {"worker": ["worker4:2222", "worker5:2222"]}
      )
      cluster_spec_2 = server_lib.ClusterSpec(
          {"worker": ["worker0:2222", "worker1:2222", "worker2:2222"]}
      )
      cluster_resolver_1 = cluster_resolver.SimpleClusterResolver(
          cluster_spec_1
      )
      cluster_resolver_2 = cluster_resolver.SimpleClusterResolver(
          cluster_spec_2
      )
  
      union_cluster = cluster_resolver.UnionClusterResolver(
          cluster_resolver_1, cluster_resolver_2
      )
      cluster_spec = union_cluster.cluster_spec()
  
      expected_proto = """
      job { name: 'worker' tasks { key: 0 value: 'worker4:2222' }
                           tasks { key: 1 value: 'worker5:2222' }
                           tasks { key: 2 value: 'worker0:2222' }
                           tasks { key: 3 value: 'worker1:2222' }
                           tasks { key: 4 value: 'worker2:2222' } }
      """
      self._verifyClusterSpecEquality(cluster_spec, expected_proto)
  
imports: from tensorflow.python.client import session
  from tensorflow.python.distribute.cluster_resolver import cluster_resolver
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.framework import test_util
  from tensorflow.python.platform import test
  from tensorflow.python.training import server_lib
label_desc: Use image node_id 11 for calling the UnionClusterResolverTest obj's underlying member method code with example usage: obj.testOverlappingJobMergedClusterResolver() without return types