/// <summary>
        /// Init all managers
        /// </summary>
        private void Init(PdfDictionary form)
        {
            PdfResources resources = null;

            if (form != null)
            {
                var resourcesDict = form.Elements.GetDictionary(PdfKeys.Resources);
                resources = new PdfResources(resourcesDict);
            }

            extendedStatesManager = new ExtendedStatesManager();
            extendedStatesManager.Init(resources);

            fontManager = new FontManager();
            fontManager.Init(resources);

            patternManager = new PatternManager();
            patternManager.Init(resources);

            colorSpaceManager = new ColorSpaceManager(patternManager);
            colorSpaceManager.Init(resources);

            shadingManager = new ShadingManager();
            shadingManager.Init(resources);

            xObjectManager = new XObjectManager();
            xObjectManager.Init(resources);
        }