code: private void markUnusedParameters(Node paramList, Scope fparamScope) {
      for (Node param = paramList.getFirstChild(); param != null; param = param.getNext()) {
        if (param.isUnusedParameter()) {
          continue;
        }
  
        Node lValue = nameOfParam(param);
        if (lValue == null) {
          continue;
        }
  
        VarInfo varInfo = traverseNameNode(lValue, fparamScope);
        if (varInfo.isRemovable()) {
          param.setUnusedParameter(true);
          compiler.reportChangeToEnclosingScope(paramList);
        }
      }
    }
docs: Mark any remaining unused parameters as being unused so it can be used elsewhere.
  
  @param paramList list of function's parameters
  @param fparamScope