title: String that cannot be represented in UTF-8
body: <p>I am creating a set of tests for the size of a <code>String</code> to do so I am using something like this <code>myString.getBytes("UTF-8").length &gt; MAX_SIZE</code> for which java has a checked exception <code>UnsupportedEncodingException</code>.</p>
  
  <p>Just for curiosity, and to further consider other possible test scenarios, is there a text that cannot be represented by UTF-8 character encoding?</p>
  
  <p>BTW: I did my homework, but nowhere (that I can find) specifies that indeed UTF-8/Unicode includes ALL the characters which are possible. I know that its size is 2^32 and many of them are still empty, but the question remains.</p>