code: def test_convert_stock():
      """
      Tests get_symbol function,
      get_symbol should return appropriate string
      corresponding to abbreviation.
      This string will be a company's full name,
      and the abbreviation will be the NSYE
      symbol for the company.
  
      Example:
          print(get_symbol("aapl"))
          console >> Apple Inc.
  
      If the symbol does not have a corresponding
      company, Nonetype should be returned.
      """
      assert get_symbol("GME") == "GameStop Corp."
      assert get_symbol("AAPL") != "Aramark"
      assert get_symbol("ASNF") is None
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_convert_stock() without return types