docs: function buildJS(src, filename, dest, applyHeader, forceIncludePaths) {
    dest = dest || config.dist.jsPath;
    applyHeader = applyHeader || false;
    forceIncludePaths = forceIncludePaths || false;
  
    return gulp.src(src)
      .pipe(gulpif(
        forceIncludePaths,
        include({
          includePaths: [
            path.dirname(src),
            __dirname,
            config.packagesPath
          ]
        }),
        include()
      ))
      .on('error', console.log) // eslint-disable-line no-console
      .pipe(babel())
      .pipe(uglify({
        output: {
          // try to preserve non-standard headers (e.g. from objectFitPolyfill)
          comments: /^(!|---)/
        }
      }))
      .pipe(gulpif(applyHeader, header(config.prj.header, {
        config: config
      })))
      .pipe(rename(filename))
      .pipe(gulp.dest(dest));
  }