public Stream<ExplorerActionHandler> stream() {
        return getHandlers()
                .allHandlers
                .values()
                .stream()
                .filter(Objects::nonNull);
    }
@param consumer {@link BiConsumer} of the document type and {@link ExplorerActionHandler}
stroom-explorer/stroom-explorer-impl/src/main/java/stroom/explorer/impl/ExplorerActionHandlers.java