+ * @param observedTimestamp observedTimestamp
+ */
+ void saveData(String dataspaceName, String anchorName, String jsonData, OffsetDateTime observedTimestamp);
+
+ /**
+ * Persists child data fragment under existing data node for the given anchor and dataspace.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param parentNodeXpath parent node xpath
+ * @param jsonData json data
+ * @param observedTimestamp observedTimestamp
+ */
+ void saveData(String dataspaceName, String anchorName, String parentNodeXpath, String jsonData,
+ OffsetDateTime observedTimestamp);
+
+ /**
+ * Persists child data fragment representing one or more list elements under existing data node for the
+ * given anchor and dataspace.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param parentNodeXpath parent node xpath
+ * @param jsonData json data representing list element(s)
+ * @param observedTimestamp observedTimestamp
+ */
+ void saveListElements(String dataspaceName, String anchorName, String parentNodeXpath, String jsonData,
+ OffsetDateTime observedTimestamp);
+
+ /**
+ * Retrieves datanode by XPath for given dataspace and anchor.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param xpath xpath
+ * @param fetchDescendantsOption defines the scope of data to fetch: either single node or all the descendant nodes
+ * (recursively) as well
+ * @return data node object
+ */
+ DataNode getDataNode(String dataspaceName, String anchorName, String xpath,
+ FetchDescendantsOption fetchDescendantsOption);
+
+ /**
+ * Updates data node for given dataspace and anchor using xpath to parent node.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param parentNodeXpath xpath to parent node
+ * @param jsonData json data
+ * @param observedTimestamp observedTimestamp
+ */
+ void updateNodeLeaves(String dataspaceName, String anchorName, String parentNodeXpath, String jsonData,
+ OffsetDateTime observedTimestamp);
+
+ /**
+ * Replaces existing data node content including descendants.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param parentNodeXpath xpath to parent node
+ * @param jsonData json data
+ * @param observedTimestamp observedTimestamp
+ */
+ void replaceNodeTree(String dataspaceName, String anchorName, String parentNodeXpath, String jsonData,
+ OffsetDateTime observedTimestamp);
+
+ /**
+ * Replaces list content by removing all existing elements and inserting the given new elements as json
+ * under given parent, anchor and dataspace.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param parentNodeXpath parent node xpath
+ * @param jsonData json data representing the new list elements
+ * @param observedTimestamp observedTimestamp
+ */
+ void replaceListContent(String dataspaceName, String anchorName, String parentNodeXpath, String jsonData,
+ OffsetDateTime observedTimestamp);
+
+ /**
+ * Replaces list content by removing all existing elements and inserting the given new elements as data nodes
+ * under given parent, anchor and dataspace.
+ *
+ * @param dataspaceName dataspace-name
+ * @param anchorName anchor name
+ * @param parentNodeXpath parent node xpath
+ * @param dataNodes datanodes representing the updated data
+ * @param observedTimestamp observedTimestamp
+ */
+ void replaceListContent(String dataspaceName, String anchorName, String parentNodeXpath,
+ Collection<DataNode> dataNodes, OffsetDateTime observedTimestamp);
+
+ /**
+ * Deletes data node for given anchor and dataspace.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param dataNodeXpath data node xpath
+ * @param observedTimestamp observed timestamp
+ */
+ void deleteDataNode(String dataspaceName, String anchorName, String dataNodeXpath,
+ OffsetDateTime observedTimestamp);
+
+ /**
+ * Deletes all data nodes for a given anchor in a dataspace.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param observedTimestamp observed timestamp
+ */
+ void deleteDataNodes(String dataspaceName, String anchorName, OffsetDateTime observedTimestamp);
+
+ /**
+ * Deletes a list or a list-element under given anchor and dataspace.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param listElementXpath list element xpath
+ * @param observedTimestamp observedTimestamp
+ */
+ void deleteListOrListElement(String dataspaceName, String anchorName, String listElementXpath,
+ OffsetDateTime observedTimestamp);
+
+ /**
+ * Updates leaves of DataNode for given dataspace and anchor using xpath, along with the leaves of each Child Data
+ * Node which already exists. This method will throw an exception if data node update or any descendant update does
+ * not exist.
+ *
+ * @param dataspaceName dataspace name
+ * @param anchorName anchor name
+ * @param parentNodeXpath xpath
+ * @param dataNodeUpdatesAsJson json data representing data node updates
+ * @param observedTimestamp observedTimestamp
+ */
+ void updateNodeLeavesAndExistingDescendantLeaves(String dataspaceName, String anchorName, String parentNodeXpath,
+ String dataNodeUpdatesAsJson, OffsetDateTime observedTimestamp);
+
+ /**
+ * Starts a session which allows use of locks and batch interaction with the persistence service.
+ *
+ * @return Session ID string
+ */
+ String startSession();
+
+ /**
+ * Close session.
+ *
+ * @param sessionId session ID
+ *