diff --git a/src/Facade/Requests/CalDAVRequestFactory.php b/src/Facade/Requests/CalDAVRequestFactory.php
index 139856d..738b6fd 100644
--- a/src/Facade/Requests/CalDAVRequestFactory.php
+++ b/src/Facade/Requests/CalDAVRequestFactory.php
@@ -16,34 +16,31 @@
  * Class CalDAVRequestFactory
  * @package CalDAVClient\Facade\Requests
  */
-final class CalDAVRequestFactory
+final class CalDAVRequestFactory implements ICalDAVRequestFactory
 {
-    const PrincipalRequestType        = 'PRINCIPAL';
-    const CalendarHomeRequestType     = 'CALENDAR_HOME';
-    const CalendarsRequestType        = 'CALENDARS';
-    const CalendarRequestType         = 'CALENDAR';
-    const CalendarSyncRequestType     = 'CALENDAR_SYNC';
-    const CalendarMultiGetRequestType = 'CALENDAR_MULTIGET';
-    const CalendarQueryRequestType    = 'CALENDAR_QUERY';
-    const CalendarCreateRequestType   = 'CREATE_CALENDAR';
-    const EventCreateRequestType      = 'CREATE_EVENT';
-    const EventUpdateRequestType      = 'UPDATE_EVENT';
-
     private function __construct(){}
 
     /**
-     * @var CalDAVRequestFactory
+     * @var ICalDAVRequestFactory
      */
     private static $instance;
 
     /**
-     * @return CalDAVRequestFactory
+     * @return ICalDAVRequestFactory
      */
     public static function getInstance(){
         if(is_null(self::$instance)) self::$instance = new CalDAVRequestFactory();
         return self::$instance;
     }
 
+    /**
+     * Override which class is used to create new request objects.
+     * @param ICalDAVRequestFactory $factory
+     */
+    public static function setInstance(ICalDAVRequestFactory $factory) {
+        self::$instance = $factory;
+    }
+
     /**
      * @param string $type
      * @param array $params
diff --git a/src/Facade/Requests/ICalDAVRequestFactory.php b/src/Facade/Requests/ICalDAVRequestFactory.php
new file mode 100644
index 0000000..96458f8
--- /dev/null
+++ b/src/Facade/Requests/ICalDAVRequestFactory.php
@@ -0,0 +1,40 @@
+<?php namespace CalDAVClient\Facade\Requests;
+/**
+ * Copyright 2019 OpenStack Foundation
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+/**
+ * Interface ICalDAVRequestFactory
+ * @package CalDAVClient\Facade\Requests
+ */
+interface ICalDAVRequestFactory {
+    const PrincipalRequestType        = 'PRINCIPAL';
+    const CalendarHomeRequestType     = 'CALENDAR_HOME';
+    const CalendarsRequestType        = 'CALENDARS';
+    const CalendarRequestType         = 'CALENDAR';
+    const CalendarSyncRequestType     = 'CALENDAR_SYNC';
+    const CalendarMultiGetRequestType = 'CALENDAR_MULTIGET';
+    const CalendarQueryRequestType    = 'CALENDAR_QUERY';
+    const CalendarCreateRequestType   = 'CREATE_CALENDAR';
+    const EventCreateRequestType      = 'CREATE_EVENT';
+    const EventUpdateRequestType      = 'UPDATE_EVENT';
+
+    /**
+     * Builds a request of a certain type.
+     *
+     * @param string $type
+     * @param array $params
+     * @return IAbstractWebDAVRequest|null
+     * @throws \InvalidArgumentException
+     */
+    public function build($type, $params = []);
+}
diff --git a/src/Facade/Responses/GenericSinglePROPFINDCalDAVResponse.php b/src/Facade/Responses/GenericSinglePROPFINDCalDAVResponse.php
index bf73454..c246ff9 100644
--- a/src/Facade/Responses/GenericSinglePROPFINDCalDAVResponse.php
+++ b/src/Facade/Responses/GenericSinglePROPFINDCalDAVResponse.php
@@ -89,6 +89,20 @@ public function getHRef()
         return isset($this->content['response']['href']) ? $this->content['response']['href'] : null;
     }
 
+    /**
+     * @return array
+     */
+    public function getFoundProps() {
+        return $this->found_props;
+    }
+
+    /**
+     * @return array
+     */
+    public function getNotFoundProps() {
+        return $this->not_found_props;
+    }
+
     /**
      * @return bool
      */