code: def get_d3_url(self):
      return DEFAULT_D3_URL if self.d3_url is None else self.d3_url
  
imports: import pkgutil
  from typing import Tuple
  from scattertext.Common import DEFAULT_D3_URL, DEFAULT_D3_SCALE_CHROMATIC, DEFAULT_HTML_VIZ_FILE_NAME, AUTOCOMPLETE_CSS_FILE_NAME, SEARCH_FORM_FILE_NAME
  from scattertext.viz.ScatterplotStructure import InvalidProtocolException
label_desc: Use image node_id 2 for calling the D3URLs obj's underlying member method code with example usage: obj.get_d3_url() and returns: unknown