@SuppressWarnings("unchecked")
    public final <T> T getUserData(String key, T defaultValue) {
        return (T) userData.getOrDefault(key, defaultValue);
    }
Gets user data associated with this input stream.

@param <T>          type of the value
@param key          key
@param defaultValue default value
@return value, could be null
clickhouse-data/src/main/java/com/clickhouse/data/ClickHouseInputStream.java