/// <summary>
 /// Validates provided parsed option for compliance with this option definition.
 /// </summary>
 /// <param name="parsedOption">parsed option that should be validated</param>
 /// <returns>true if the provided option is valid; otherwise returns false</returns>
 internal ValueValidationResult Validate(OptionParsed parsedOption)
 {
     if (parsedOption.Value == null)
     {
         return(ValueValidationResult.OK);
     }
     if (_valueParser == null)
     {
         throw new Exception("Internal Error");
     }
     return(_valueParser.ValidateValue(parsedOption.Value));
 }