Question for the programmers I know: Let's say you're writing a utility for quickly attaching a lot of strings together into one bigger string. And let's further say you need to figure out how to handle the case that one of those strings might be uninitialized. What sort of options might you consider to deal with the scenario?
Java's StringBuilder.append(String str) has a very interesting solution I definitely would not have come up with on my own: https://docs.oracle.com/javase/1.5.0/docs/api/java/lang/StringBuilder.html#append(java.lang.String)
StringBuilder (Java 2 Platform SE 5.0)

@VDOPlus to be fair, i do think that's the official toString representation of a null object so it's definitely consistent with the rest of the java API