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

        Histogram histogram = (Histogram) o;

        if (schema != histogram.schema) return false;

        return true;
    }
@author emeroad
@author netspider
@author jaehong.kim
web/src/main/java/com/navercorp/pinpoint/web/applicationmap/histogram/Histogram.java