public static void checkArg(boolean isOK, String s) {
        if (!isOK) {
            throw new IllegalArgumentException(s);
        }
    }
A set of methods to support some sort of "Design by Contract" programming.

@author Udo Borkowski (ub@abego.org)
stroom-core-client-widget/src/main/java/stroom/widget/htree/client/treelayout/internal/util/Contract.java