Function extract_optional_string_column_by_name 

pub fn extract_optional_string_column_by_name<'a>(
    record_batch: &'a RecordBatch,
    column_key: &'static str,
) -> Result<Option<&'a StringArray>, EncodingError>

Extracts an optional UTF-8 column by name.

Errors

Returns an error if the column exists but is not UTF-8.