@Override
    public boolean equals(Object obj) {
        if (!(obj instanceof ErrorDirective)) {
            return false;
        }
        ErrorDirective rhs = (ErrorDirective)obj;
        if (!msg.equals(rhs.msg)) {
            return false;
        }
        return true;
    }
Returns the error string that is to be assigned to the reply.

@return The error string.
messagebus/src/main/java/com/yahoo/messagebus/routing/ErrorDirective.java