Test 1: Verify that a header at the beginning of inserted content is preserved.
Success. <h1>bar</h1><div>baz</div> was inserted into <div>foo^foo<div> and the result was:foo<h1>bar</h1>bazfoo
Success. <h2>bar</h2><div>baz</div> was inserted into <div>foo^foo<div> and the result was:foo<h2>bar</h2>bazfoo
Success. <h3>bar</h3><div>baz</div> was inserted into <div>foo^foo<div> and the result was:foo<h3>bar</h3>bazfoo
Success. <h4>bar</h4><div>baz</div> was inserted into <div>foo^foo<div> and the result was:foo<h4>bar</h4>bazfoo
Success. <h5>bar</h5><div>baz</div> was inserted into <div>foo^foo<div> and the result was:foo<h5>bar</h5>bazfoo
Success. <h6>bar</h6><div>baz</div> was inserted into <div>foo^foo<div> and the result was:foo<h6>bar</h6>bazfoo
Test 2: Verify that a header at the end of inserted content is preserved.
Success. <div>bar</div><h1>baz</h1> was inserted into <div>foo^foo<div> and the result was:foobar<h1>baz</h1>foo
Success. <div>bar</div><h2>baz</h2> was inserted into <div>foo^foo<div> and the result was:foobar<h2>baz</h2>foo
Success. <div>bar</div><h3>baz</h3> was inserted into <div>foo^foo<div> and the result was:foobar<h3>baz</h3>foo
Success. <div>bar</div><h4>baz</h4> was inserted into <div>foo^foo<div> and the result was:foobar<h4>baz</h4>foo
Success. <div>bar</div><h5>baz</h5> was inserted into <div>foo^foo<div> and the result was:foobar<h5>baz</h5>foo
Success. <div>bar</div><h6>baz</h6> was inserted into <div>foo^foo<div> and the result was:foobar<h6>baz</h6>foo

