• Add Rest end-point for Update method
• Add API interface methods for same
• Add SPI interface method for same
• Ensure Open API documentation is updated (if in place)
• Response object is JSON
• Add error handling if needed

Following Ruslan's study (https://wiki.onap.org/display/DW/CPS-222%3A+Spike%3A+CPS+data+update+options) The following approach wil be used:

• Update will replace an existing DataNode including all its leaves (and leaflists)
• Whether or not its children wil be replaced can be controlled with a parameter

Out-of-scope

• Input and output data format are inconsistent (see issue #... in [the study|https://wiki.onap.org/display/DW/CPS-222%3A+Spike%3A+CPS+data+update+options))] This will NOT be addressed as part of this user story
• Adding or removing from a List of DataNodes is not in scope. This user story will only allow for replacing a complete list through its parent container
• Updating a single attribute is not possible. All other attributes that are not changed will have to be re-supplied as part of the replacement DataNode provided to the interface