src/vs/workbench/api/common/extHostFileSystemConsumer.ts/ExtHostConsumerFileSystem/addFileSystemProvider
class ExtHostConsumerFileSystem:	addFileSystemProvider(scheme: string, provider: vscode.FileSystemProvider): IDisposable {
		this._fileSystemProvider.set(scheme, provider);
		return toDisposable(() => this._fileSystemProvider.delete(scheme));
	}