The methods Concat (all the methods in oveloading) of the IRALibrary

String class now return the object, so it's possible to perform more 
concatenations at the same time. For instance: 
    obj.Concat(first).Concat(second).Concat(third);
insted of:
    obj.Concat(first);
    obj.Concat(second);
    obj.Concat(third);