@Override public String toString() { final StringBuilder sb = new StringBuilder(getClass().getName()); sb.append("@").append(System.identityHashCode(this)).append("{"); sb.append("statisticIds=").append(this.statisticIds); sb.append(", listeners=").append(this.listeners); final StringBuilder toAppend = appendToString(); if (toAppend == null) { sb.append(", ").append(toAppend); } sb.append("}"); return sb.toString(); }