private static int getFunExprParameterCount(LighterAST tree, LighterASTNode funExpr) {
    if (funExpr.getTokenType() == METHOD_REF_EXPRESSION) return FunctionalExpressionKey.UNKNOWN_PARAM_COUNT;

    assert funExpr.getTokenType() == LAMBDA_EXPRESSION;

    LighterASTNode paramList = LightTreeUtil.firstChildOfType(tree, funExpr, PARAMETER_LIST);
    assert paramList != null;
    return LightTreeUtil.getChildrenOfType(tree, paramList, Constants.PARAMETER_BIT_SET).size();
  }
private static int getFunExprParameterCount(LighterAST tree, LighterASTNode funExpr)