* Returns the content charset passed by the agent or null if not defined.
*
* @return The content charset passed by the agent or null if not defined
*/
public String getCharSet() {
ParameterParser parser = new ParameterParser();
parser.setLowerCaseNames(true);
// Parameter parser can handle null input
Map<?, ?> params = parser.parse(getContentType(), ';');
return (String) params.get("charset");
}