You have asked to write an extended version of the standard HelloWorld, named "MultiGreeter". A MultiGreeter can have multiple greetings. By default a MultiGreeter has the greeting "Hello, World!" A user can add any string as a greeting. Duplicatss are allowed, however nulls are not. A user can get the current number of greetings in the MultiGreeter A user can also request to get the greetings of a MultiGreeter and will receive an array of its current greeting