+ /**
+ * Reads data from the provided logical data store located at the provided path.
+ *
+ * <p>
+ * If the target is a subtree, then the whole subtree is read (and will be accessible from the returned data
+ * object).
+ *
+ * @param store Logical data store from which read should occur.
+ * @param path Path which uniquely identifies subtree which client want to read
+ * @return a CheckFuture containing the result of the read. The Future blocks until the
+ * commit operation is complete. Once complete:
+ * <ul>
+ * <li>If the data at the supplied path exists, the Future returns an Optional object
+ * containing the data.</li>
+ * <li>If the data at the supplied path does not exist, the Future returns
+ * Optional#absent().</li>
+ * <li>If the read of the data fails, the Future will fail with a
+ * {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
+ * </ul>
+ */
+ <T extends DataObject> CheckedFuture<Optional<T>, ReadFailedException> read(
+ LogicalDatastoreType store, InstanceIdentifier<T> path);
+
+ /**
+ * Checks if data is available in the logical data store located at provided path.
+ *
+ * <p>
+ * Note: a successful result from this method makes no guarantee that a subsequent call to {@link #read}
+ * will succeed. It is possible that the data resides in a data store on a remote node and, if that
+ * node goes down or a network failure occurs, a subsequent read would fail. Another scenario is if
+ * the data is deleted in between the calls to <code>exists</code> and <code>read</code>
+ *
+ * <p>
+ * Default implementation delegates to {@link #read(LogicalDatastoreType, InstanceIdentifier)}, implementations
+ * are advised to provide a more efficient override.
+ *
+ * @param store Logical data store from which read should occur.
+ * @param path Path which uniquely identifies subtree which client want to check existence of
+ * @return a CheckFuture containing the result of the check.
+ * <ul>
+ * <li>If the data at the supplied path exists, the Future returns a Boolean
+ * whose value is true, false otherwise</li>
+ * <li>If checking for the data fails, the Future will fail with a
+ * {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
+ * </ul>
+ */
+ default CheckedFuture<Boolean, ReadFailedException> exists(final LogicalDatastoreType store,
+ final InstanceIdentifier<?> path) {
+ return MappingCheckedFuture.create(Futures.transform(read(store, path), Optional::isPresent,
+ MoreExecutors.directExecutor()), ReadFailedException.MAPPER);
+ }