protected void ThrowUnmappablePropertyTypeException(string propertyName, string pageTypeName)
{
string errorMessage = "Unable to find a valid EPiServer property type for the property {0} in the page type {1}";
errorMessage = string.Format(CultureInfo.InvariantCulture, errorMessage, propertyName, pageTypeName);
throw new UnmappablePropertyTypeException(errorMessage);
}