docs: public IsInRecipientBlacklistResponse isInRecipientBlacklist(IsInRecipientBlacklistRequest request) {
          checkNotNull(request, "object request should not be null.");
          assertStringNotNullOrEmpty(request.getEmailAddress(), "object emailAddress should not be null or empty");
  
          InternalRequest internalRequest =
                  this.createRequest("recipientBlacklist", request, HttpMethodName.GET, request.getEmailAddress());
          return this.invokeHttpClient(internalRequest, IsInRecipientBlacklistResponse.class);
      }