public void Validate() { if (_fromQuantity != null) { _fromQuantity.Validate(); } if (_toQuantity != null) { _toQuantity.Validate(); } if (_errorLimit != null) { _errorLimit.Validate(); } Regex regx = new Regex(PATTERN); if (!regx.Match(ToString()).Success) { throw new Exception(string.Format("Invalid Physical Expression - {0}", ToString())); } }