code: def test_ret_const():
      a = tir.const(0)
      b = tir.ret(a)
      b = tir.Evaluate(b)
      func = tir.PrimFunc([], b)
      func = build_tir_func(func)
      out = func()
      assert out == 0
  
file_path: tvm/tests/python/tir-base/test_tir_base.py
imports: import tvm
  import pytest
  from tvm import tir
  from tvm._ffi.base import TVMError
  from tvm.ir.transform import PassContext
  import itertools
  import pytest
label_desc: Use image node_id 6 for calling a global function with example usage: test_ret_const() without return types