title: Trim string by strings
body: <p>How can I trim a string by a whole string instead of a list of single characters?  </p>
  
  <p>I want to remove all <code>&amp;nbsp;</code> and whitespaces at beginning and end of an HTML string. But method <code>String.Trim()</code> does only have overloads for set of characters and not for set of strings.</p>