@Override
        @SuppressWarnings("ConstantConditions")
        public Set<String> keySet() {
            // TODO: create a view in Schema
            return schemaRef.get().getColumns().stream().map(ClickHouseColumn::getColumnName).collect(Collectors.toSet());
        }
Converts value in to a string representation. Does some formatting for selected data types
@return string representation of a value for specified column
client-v2/src/main/java/com/clickhouse/client/api/data_formats/internal/AbstractBinaryFormatReader.java