enum stream = {stdout, stderr, both}
class Helpers{
  static exec(command: String, args: Array<string> = [], options: Object = {stream: 'stdout'})
  static execNode(filePath: String, args: Array<string> = [], options: Object = {stream: 'stdout'})
  static parse(data: String, regex: String, options: Object = {baseReduction: 1, flags: ""})
  static rangeFromLineNumber(textEditor: TextEditor, lineNumber: Number):Range
  static findFile(directory:String, names: String | Array<string>): ?String
  static findFileAsync(directory: Strng, names: String | Array<string>): Promise<?String>
  static tempFile<T>(filePath:String, fileContents:String, Callback:Function<T>):Promise<T>
  static createElement(tagName: string): HTMLElement
}