code: def test_na_empty_str_elem_option(parser, geom_df):
      output = geom_df.to_xml(na_rep="", parser=parser)
      output = equalize_decl(output)
  
      assert output == na_expected
  
imports: from __future__ import annotations
  from io import BytesIO, StringIO
  import os
  import numpy
  import pytest
  import pandas.util._test_decorators
  from pandas import NA, DataFrame, Index
  import pandas._testing
  from pandas.io.common import get_handle
  from pandas.io.xml import read_xml
label_desc: Use image node_id 15 for calling a global function with example usage: test_na_empty_str_elem_option(parser, geom_df) without return types