code: def test_free_vars():
      ty = relay.TensorType([], "int32")
      x = relay.Var("x", ty)
      fvx = free_vars(x)
      assert len(fvx) == 1
      assert fvx[0] == x
      v = relay.Constant(tvm.nd.array(10))
  
      let = relay.Let(x, v, x)
      fvx = free_vars(let)
      assert len(free_vars(let)) == 0
      f = relay.Function([x], x, ty)
      assert len(free_vars(f)) == 0
  
file_path: tvm/tests/python/relay/test_pass_vars.py
imports: import tvm
  from tvm import te
  from tvm import relay
  from tvm.relay.analysis import free_vars, free_type_vars, bound_vars, bound_type_vars, all_vars, all_type_vars
label_desc: Use image node_id 2 for calling a global function with example usage: test_free_vars() without return types