Map<IKey, ParameterDescription> used with containsKey(String)

[lindenb]

If I'm not wrong in https://github.com/cbeust/jcommander/blob/master/src/main/java/com/beust/jcommander/JCommander.java#L652

 if (descriptions.containsKey(name)) {

description is a Map<IKey, ParameterDescription> and it's compared to a String.

the implementations of IKey.equals in StringKey or ProgramName don't handle the String.class