def _MarkLocalVariableUsed(self, identifier):
    identifier = identifier.split('.', 1)[0]
    # Find the first instance of the identifier in the stack of function scopes
    # and mark it used.
    for unused_local_variables in reversed(
        self._unused_local_variables_by_scope):
      if identifier in unused_local_variables:
        del unused_local_variables[identifier]
        break
Used to send the Message-Id of a received email back as In-Reply-To
dataset/ETHPy150Open google/closure-linter/closure_linter/javascriptlintrules.py/JavaScriptLintRules._MarkLocalVariableUsed--crossover with--dataset/ETHPy150Open frappe/frappe/frappe/email/email_body.py/EMail.set_in_reply_to