Some adapters may facilitate exporting data locally. By setting the COPY_FORMATS class variable on their subclass of HarlequinAdapter and implementing HarlequinConnection.copy(), they can enable their users to use Harlequin’s Data Exporter UI.
COPY_FORMATS is a list of HarlequinCopyFormat instances, which define a name, label, one or more file extensions associated with the format, and a list of AbstractOption subclass instances that define options for the format. For more information, see the source in the harlequin.options module, or the DuckDB implementation.
Copy Formats (from the Harlequin docs)