code: def test_rename_symbols_global(self):
      node = parser.parse("global a, b, c")
      node = qual_names.resolve(node)
  
      node = ast_util.rename_symbols(
          node, {qual_names.from_str("b"): qual_names.QN("renamed_b")}
      )
  
      source = parser.unparse(node, include_encoding_marker=False)
      self.assertEqual(source.strip(), "global a, renamed_b, c")
  
imports: import ast
  import collections
  import textwrap
  import unittest
  import gast
  from nvidia.dali._autograph.pyct import anno
  from nvidia.dali._autograph.pyct import ast_util
  from nvidia.dali._autograph.pyct import loader
  from nvidia.dali._autograph.pyct import parser
  from nvidia.dali._autograph.pyct import pretty_printer
  from nvidia.dali._autograph.pyct import qual_names
label_desc: Use image node_id 6 for calling the AstUtilTest obj's underlying member method code with example usage: obj.test_rename_symbols_global() without return types