code: def _getExternalValues(t, *args):
      t.run_build_system(["---var-name=%s" % x for x in args])
      result = dict()
      for x in args:
          m = re.search(
              r"^\*\*\*ENV\*\*\* %s: '(.*)' \*\*\*$" % x,
              t.stdout(),
              re.MULTILINE,
          )
          if m:
              result[x] = m.group(1)
          else:
              result[x] = None
      return result
  
file_path: turicreate/src/external/boost/boost_1_68_0/tools/build/test/collect_debug_info.py
imports: import BoostBuild
  import os
  import re
  import sys
label_desc: Use image node_id 4 for calling a global function with example usage: _getExternalValues(t) and returns: result