### Question:
OAuthResponseParams { public void addToResponse(HttpResponseBuilder response, OAuthRequestException e) { if (!newClientState.isEmpty()) { try { response.setMetadata(CLIENT_STATE, newClientState.getEncryptedState()); } catch (BlobCrypterException cryptException) { throw new RuntimeException(cryptException); } } if (aznUrl != null) { response.setMetadata(APPROVAL_URL, aznUrl); } if (e != null || sendTraceToClient) { StringBuilder verboseError = new StringBuilder(); if (e != null) { response.setMetadata(ERROR_CODE, e.getError()); verboseError.append(e.getErrorText()); } if (sendTraceToClient) { verboseError.append('\n'); verboseError.append(getRequestTrace()); } response.setMetadata(ERROR_TEXT, verboseError.toString()); } } OAuthResponseParams(SecurityToken securityToken, HttpRequest originalRequest,
      BlobCrypter stateCrypter); void logDetailedWarning(String note); void logDetailedWarning(String note, Throwable e); void logDetailedInfo(String note, Throwable e); void addRequestTrace(HttpRequest request, HttpResponse response); boolean sawErrorResponse(); void addToResponse(HttpResponseBuilder response, OAuthRequestException e); OAuthClientState getNewClientState(); String getAznUrl(); void setAznUrl(String aznUrl); boolean sendTraceToClient(); void setSendTraceToClient(boolean sendTraceToClient); static final String CLIENT_STATE; static final String APPROVAL_URL; static final String ERROR_CODE; static final String ERROR_TEXT; }### Answer:
@Test public void testAddEmptyParams() { HttpResponseBuilder responseBuilder = new HttpResponseBuilder(); params.addToResponse(responseBuilder, null); HttpResponse response = responseBuilder.create(); assertTrue(response.getMetadata().isEmpty()); }