src/vs/workbench/api/common/extHostSearch.ts/ExtHostSearch/createTextSearchManager
class ExtHostSearch:	protected createTextSearchManager(query: ITextQuery, provider: vscode.TextSearchProvider): TextSearchManager {
		return new TextSearchManager(query, provider, {
			readdir: resource => Promise.resolve([]), // TODO@rob implement
			toCanonicalName: encoding => encoding
		}, 'textSearchProvider');
	}