public void delete(String name) throws IOException {
  if (name.equalsIgnoreCase(DATE)) {
    date=null;
  }
 else {
    throw new IOException("Name not supported by InvalidityDateExtension");
  }
  encodeThis();
}

public void delete ( String name ) throws IOException { if ( name . equalsIgnoreCase ( DATE ) ) { date = null ; } else { throw new IOException ( "Name not supported by InvalidityDateExtension" ) ; } encodeThis ( ) ; }
delete the attribute value .
