src/vs/workbench/api/common/extHostLanguageFeatures.ts/DocumentOnDropAdapter/provideDocumentOnDropEdits
class DocumentOnDropAdapter:	async provideDocumentOnDropEdits(uri: URI, position: IPosition, dataTransferDto: DataTransferDTO, token: CancellationToken): Promise<Dto<languages.SnippetTextEdit> | undefined> {
		const doc = this._documents.getDocument(uri);
		const pos = typeConvert.Position.to(position);
		const dataTransfer = DataTransferConverter.toDataTransfer(dataTransferDto);

		const edit = await this._provider.provideDocumentOnDropEdits(doc, pos, dataTransfer, token);
		if (!edit) {
			return undefined;
		}
		return typeConvert.SnippetTextEdit.from(edit);
	}