@Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((this.learners == null) ? 0 : this.learners.hashCode());
        result = prime * result + ((this.peers == null) ? 0 : this.peers.hashCode());
        return result;
    }
Returns the peers total number.

@return total num of peers
jraft-core/src/main/java/com/alipay/sofa/jraft/conf/Configuration.java