PsiExpression (PsiCall call) { PsiExpressionList argList = call.getArgumentList(); if (argList == null) return null; PsiExpression[] args = argList.getExpressions(); if (args.length != 1) return null; return ExpressionUtils.isLiteral(PsiUtil.skipParenthesizedExprDown(args[0]), "") ? args[0] : null; }