/*
         * Removal.
         */

        /// <summary>
        /// Unregisters the handler registered for a document type specified as a
        /// DocumentType object.
        /// </summary>
        /// <param name="documentType">The document type.</param>
        /// <returns>The open document handler or null if the document type is invalid or
        /// no handler exists for the type.</returns>
        public OpenDocumentHandler RemoveOpenDocumentHandler(
            DocumentType documentType)
        {
            return(RemoveOpenDocumentHandler(documentType.ToString()));
        }
        /*
         * Registration.
         */

        /// <summary>
        /// Registers an open document handler for a document type provided as a DocumentType object.
        /// A handler will be rejected if a handler has already been registered for the document type.
        /// </summary>
        /// <param name="documentType">The document type to be opened by the handler.</param>
        /// <param name="handler">The handler used to open documents of the registered type.</param>
        /// <returns>True if the handler was registered successfully.</returns>
        public bool RegisterOpenDocumentHandler(
            DocumentType documentType, OpenDocumentHandler handler)
        {
            return(RegisterOpenDocumentHandler(
                       documentType.ToString(), handler));
        }