private static boolean isGetSystemProperty(
      PsiMethodCallExpression expression) {
      final PsiReferenceExpression methodExpression =
        expression.getMethodExpression();
      @NonNls final String methodName =
        methodExpression.getReferenceName();
      if (!"getProperty".equals(methodName)
          && !"getProperties".equals(methodName)
          && !"setProperty".equals(methodName)
          && !"setProperties".equals(methodName)
          && !"clearProperties".equals(methodName)
        ) {
        return false;
      }
      final PsiMethod method = expression.resolveMethod();
      if (method == null) {
        return false;
      }
      final PsiClass aClass = method.getContainingClass();
      if (aClass == null) {
        return false;
      }
      final String className = aClass.getQualifiedName();
      if (className == null) {
        return false;
      }
      return "java.lang.System".equals(className);
    }
private static boolean isGetSystemProperty(
      PsiMethodCallExpression expression)