public Builder credentials(ClickHouseCredentials credentials) {
            this.credentials = credentials;
            return this;
        }
Sets credentials will be used when connecting to this node. This is optional
as client will use {@link ClickHouseConfig#getDefaultCredentials()} to
connect to all nodes.

@param credentials credentials, null means
                   {@link ClickHouseConfig#getDefaultCredentials()}
@return this builder
clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseNode.java