   /**
     * Given `base` is `foo.bar`, `foo.bar.baz` is an descendant
     *
     * Example:
     *
     * ```
     * Polymer.Path.isDescendant('foo.bar', 'foo.bar.baz') // true
     * Polymer.Path.isDescendant('foo.bar', 'foo.bar')     // false
     * Polymer.Path.isDescendant('foo.bar', 'foo')         // false
     * ```
     *
     * @memberof Polymer.Path
     * @param {string} base Path string to test against.
     * @param {string} path Path string to test.
     * @return {boolean} True if `path` is