How to use the @aurelia/runtime-html.FragmentNodeSequence function in @aurelia/runtime-html

it(`should insert the view before the refNode under the parent of the refNode (depth=${depth},width=${width})`, function () {
          const node = ctx.dom.createElement('div');
          const fragment = createFragment(ctx, node, 0, depth, width);
          sut = new FragmentNodeSequence(ctx.dom, fragment);
          const parent = ctx.dom.createElement('div');
          const ref1 = ctx.dom.createElement('div');
          const ref2 = ctx.dom.createElement('div');
          parent.appendChild(ref1);
          parent.appendChild(ref2);
          sut.insertBefore(ref2);
          assert.strictEqual(parent.childNodes.length, width + 2, `parent.childNodes.length`);
          assert.strictEqual(fragment.childNodes.length, 0, `fragment.childNodes.length`);
          assert.strictEqual(parent.childNodes.item(0) === ref1, true, `parent.childNodes.item(0) === ref1`);
          let i = 0;
          while (i < width) {
            assert.strictEqual(parent.childNodes.item(i + 1) === sut.childNodes[i], true, `parent.childNodes.item(i + 1) === sut.childNodes[i]`);
            i++;
          }
          assert.strictEqual(parent.childNodes.item(width + 1) === ref2, true, `parent.childNodes.item(width + 1) === ref2`);
          assert.strictEqual(fragment.childNodes.length, 0, `fragment.childNodes.length`);

it(`should put the view back into the fragment (depth=${depth},width=${width})`, function () {
          const node = ctx.dom.createElement('div');
          const fragment = createFragment(ctx, node, 0, depth, width);
          sut = new FragmentNodeSequence(ctx.dom, fragment);
          const parent = ctx.dom.createElement('div');
          assert.strictEqual(parent.childNodes.length, 0, `parent.childNodes.length`);
          assert.strictEqual(fragment.childNodes.length, width, `fragment.childNodes.length`);
          parent.appendChild(fragment);
          assert.strictEqual(parent.childNodes.length, width, `parent.childNodes.length`);
          assert.strictEqual(fragment.childNodes.length, 0, `fragment.childNodes.length`);
          sut.remove();
          assert.strictEqual(parent.childNodes.length, 0, `parent.childNodes.length`);
          assert.strictEqual(fragment.childNodes.length, width, `fragment.childNodes.length`);
        });
      }

it(`should correctly assign children (depth=1,width=${width})`, function () {
        const node = ctx.dom.createElement('div');
        const fragment = createFragment(ctx, node, 0, 1, width);
        sut = new FragmentNodeSequence(ctx.dom, fragment);
        assert.strictEqual(sut.childNodes.length, width, `sut.childNodes.length`);
        assert.strictEqual(sut.childNodes[0] === sut.firstChild, true, `sut.childNodes[0] === sut.firstChild`);
        assert.strictEqual(sut.childNodes[width - 1] === sut.lastChild, true, `sut.childNodes[width - 1] === sut.lastChild`);
      });
    }

it(`should return empty array when there are no targets (depth=${depth},width=${width})`, function () {
          const node = ctx.dom.createElement('div');
          const fragment = createFragment(ctx, node, 0, depth, width);
          sut = new FragmentNodeSequence(ctx.dom, fragment);
          const actual = sut.findTargets();
          assert.strictEqual(actual.length, 0, `actual.length`);
        });

it(`should append the view to the parent (depth=${depth},width=${width})`, function () {
          const node = ctx.dom.createElement('div');
          const fragment = createFragment(ctx, node, 0, depth, width);
          sut = new FragmentNodeSequence(ctx.dom, fragment);
          const parent = ctx.dom.createElement('div');
          sut.appendTo(parent);
          assert.strictEqual(parent.childNodes.length, width, `parent.childNodes.length`);
          assert.strictEqual(fragment.childNodes.length, 0, `fragment.childNodes.length`);
          let i = 0;
          while (i < width) {
            assert.strictEqual(parent.childNodes.item(i) === sut.childNodes[i], true, `parent.childNodes.item(i) === sut.childNodes[i]`);
            i++;
          }
        });
      }