masquage des collections cachées dans le treeview

            collections.forEach((c) => {

                if (c.children_count > 0)

                    c.children = []

            })

            });

            if (!context.getters.showHiddenCollections) {

                collections = collections.filter(c => {

                    return !c.title.startsWith('.')

                });

            }

            let item = findItem(id, context.state.collectionsTree);

            if (!item) {

                context.commit('setCollectionsTree', collections);