public QuerySettings httpHeader(String key, Collection<String> values) {
        rawSettings.put(ClientConfigProperties.HTTP_HEADER_PREFIX + key, ClientConfigProperties.commaSeparated(values));
        return this;
    }
{@see #httpHeader(String, String)} but for multiple values.
@param key - name of the header
@param values - collection of values
@return same instance of the builder
client-v2/src/main/java/com/clickhouse/client/api/query/QuerySettings.java