Represents the "DPart" entry of the page object object.

It is defined as part of the PDF 2.0 specification.

It contains a DocumentPartElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 30, page 77.

Adobe Supplement to the ISO 32000, BaseVersion: 1.7, ExtensionLevel: 3; Table: 3.27, page 23.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 31, page 106.

The DPart entry references the document part node in the document part hierarchy that corresponds to this page. This supports the PDF 2.0 DPart mechanism for multi-record and variable data printing documents.