No testcase making use of OPC core properties

[StefanBruens]

As far as I can see, there is no testcase making use of the package level OPC Core Properties. as mentioned in
https://github.com/3MFConsortium/spec_core/blob/master/3MF%20Core%20Specification.md#62-core-properties

Also, the specification does not mention what should be done if there is both a Package level Core Properties file and <metadata> elements in the top-level XML model file (https://github.com/3MFConsortium/spec_core/blob/master/3MF%20Core%20Specification.md#341-metadata)

a) Only the Core Properties file should be considered
b) Both should be merged
c) Extend the package with a standalone Application Properties part (like done for OPC based Office XML formats).

(a) would ignore any properties defined for 3MF, but not part of the OPC Core Properties (ECMA-376 Part 2). (3) Would cause additional overhead (rendering most of the OPC Core Properties benefits moot, raising both implementation and runtime requirements). (c) would be preferred, but is not specified.

[JimZuber]

Prior to migrating these test cases from HP to the 3MF Consortium (way back when), we did have a test case 0304_01 that included Core Properties, but for reasons lost in time it was removed, probably because there was no practical way to validate the behavior of the DUT with respect to receiving these objects. Below is the description of the now deleted test case...

01 – Add an Empty PrintTicket, empty Core Properties, and PNG Thumbnail to a 3mf file, include the root relationships to the Core Properties and Thumbnail, and 3D Model relationship for PrintTicket.

Just FYI

Regards,

Jim