code: def test_string():
      s = tvm.runtime.String("xyz")
  
      assert isinstance(s, tvm.runtime.String)
      assert isinstance(s, str)
      assert s.startswith("xy")
      assert s + "1" == "xyz1"
      y = tvm.testing.echo(s)
      assert isinstance(y, tvm.runtime.String)
      assert s.__tvm_object__.same_as(y.__tvm_object__)
      assert s == y
  
      x = tvm.ir.load_json(tvm.ir.save_json(y))
      assert isinstance(x, tvm.runtime.String)
      assert x == y
  
      # test pickle
      z = pickle.loads(pickle.dumps(s))
      assert isinstance(z, tvm.runtime.String)
      assert s == z
  
file_path: tvm/tests/python/runtime/test_runtime_container.py
imports: import numpy
  import random
  import tvm
  import tvm.testing
  import pickle
  from tvm import te
  from tvm import nd, relay
  from tvm.runtime import container
label_desc: Use image node_id 3 for calling a global function with example usage: test_string() without return types