public String getHopPrefix() {
        return getHop().getPrefix(directive);
    }
<p>Returns the part of the route string that precedes the active policy
directive. This is the same as calling {@link #getHop()}.getPrefix({@link
#getDirectiveIndex()}).</p>

@return The hop prefix.
messagebus/src/main/java/com/yahoo/messagebus/routing/RoutingContext.java