public void add(final String arg) {
        if (arg != null) {
            final Argument argument = parse(arg);
            add(argument);
        }
    }
public void add ( final String arg ) { if ( arg != null ) { final Argument argument = parse ( arg ) ; add ( argument ) ; } }
{@link #parse(String) Parses} the argument and adds it to the collection of arguments ignoring {@code null}
arguments.

@param arg the argument to add