@Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || !(o instanceof ErrorStatsData)) {
            return false;
        }

        ErrorStatsData that = (ErrorStatsData) o;

        return !(errorCause != null ? !errorCause.equals(that.errorCause) : that.errorCause != null);
    }
create a counter by route and cause of error
@param route
@param cause
zuul-core/src/main/java/com/netflix/zuul/stats/ErrorStatsData.java