code: public static ErrorCodeAttribute createErrorCodeAttribute(char errorCode,
  			String reasonPhrase) throws IllegalArgumentException {
  		ErrorCodeAttribute attribute = new ErrorCodeAttribute();
  
  		attribute.setErrorCode(errorCode);
  		attribute.setReasonPhrase(reasonPhrase == null ? ErrorCodeAttribute
  				.getDefaultReasonPhrase(attribute.getErrorCode())
  				: reasonPhrase);
  
  		return attribute;
  	}
docs: Creates an ErrorCodeAttribute with the specified error code and reason
  phrase.
  
  @param errorCode
  a valid error code.
  @param reasonPhrase
  a human readable reason phrase. A null reason phrase would be
  replaced (if possible) by a default one as defined byte the
  rfc3489.
  
  @return the newly created attribute.
  @throws IllegalArgumentException
  if errorCode is not a valid error code as defined by rfc3489