@Override
    public int hashCode() {
        final int prime = 31;
        int result = prime + checking.hashCode();
        result = prime * result + index.hashCode();
        result = prime * result + policy.hashCode();
        result = prime * result + selector.hashCode();
        result = prime * result + nodes.hashCode();
        result = prime * result + faultyNodes.hashCode();
        return result;
    }
Discovers nodes in the same cluster by querying against
{@code system.clusters} table.
clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseNodes.java