code: function flowType(src, dst) {
    var srcPath = [src+'/**/*.js',
      '!'+src+'/**/__tests__/**', '!'+src+'/**/__mocks__/**'];
    return gulp
      .src(srcPath)
      .pipe(rename({extname: '.js.flow'}))
      .pipe(gulp.dest(dst));
  }
docs: ........functions .......