public static void assertPrefix(String prefix) throws XMPException {
  if (prefix == null || prefix.length() == 0) {
    throw new XMPException("Empty prefix",XMPError.BADPARAM);
  }
}

public static void assertPrefix ( String prefix ) throws XMPException { if ( prefix == null || prefix . length ( ) == 0 ) { throw new XMPException ( "Empty prefix" , XMPError . BADPARAM ) ; } }
asserts that a prefix is set .
