code: def build_selections(*args):
      """
      simple helper function to build a single level list of values based on variable number of inputs which could be
      equal to None.
      """
      return flatten_lists(
          [[] if a is None else make_list(a) for a in args]
      )
  
file_path: dtale/dtale/dash_application/layout/utils.py
imports: import dash_bootstrap_components
  from dtale.dash_application import dcc, html
  from dtale.translations import text
  from dtale.utils import dict_merge, classify_type, flatten_lists, make_list
  from dtale.charts.utils import INDEX_COL
  from dtale.constants import CHART_JOINER_CHAR
label_desc: Use image node_id 5 for calling a global function with example usage: build_selections() and returns: flatten_lists