src/vs/workbench/api/common/extHostDocuments.ts/ExtHostDocuments/constructor
class ExtHostDocuments:	constructor(mainContext: IMainContext, documentsAndEditors: ExtHostDocumentsAndEditors) {
		this._proxy = mainContext.getProxy(MainContext.MainThreadDocuments);
		this._documentsAndEditors = documentsAndEditors;

		this._documentsAndEditors.onDidRemoveDocuments(documents => {
			for (const data of documents) {
				this._onDidRemoveDocument.fire(data.document);
			}
		}, undefined, this._toDispose);
		this._documentsAndEditors.onDidAddDocuments(documents => {
			for (const data of documents) {
				this._onDidAddDocument.fire(data.document);
			}
		}, undefined, this._toDispose);
	}