/**
* Create a new string generator which creates strings with sizes ranging
* from loLengh to hiLength of characters from a-z and A-Z.
*/
public static ExtendibleGenerator<Character, String> letterStrings(int min, int max) {
StringGenerator generator = new StringGenerator(new IntegerGenerator(min, max), characters('a', 'z'));
return generator.add(characters('A', 'Z'));
}