How to use the es6-promise/lib/es6-promise/promise.js.all function in es6-promise

this.moduleById[ source ] = module;
						}
					}

					else {
						if ( resolvedId === module.id ) {
							throw new Error( `A module cannot import itself (${resolvedId})` );
						}

						module.resolvedIds[ source ] = resolvedId;
						return this.fetchModule( resolvedId, module.id );
					}
				});
		});

		return Promise.all( promises );
	}

if ( options.sourceMap ) {
					let url;

					if ( options.sourceMap === 'inline' ) {
						url = map.toUrl();
					} else {
						url = `${basename( dest )}.map`;
						promises.push( writeFile( dest + '.map', map.toString() ) );
					}

					code += `\n//# ${SOURCEMAPPING_URL}=${url}`;
				}

				promises.push( writeFile( dest, code ) );
				return Promise.all( promises );
			}
		};