Represents the "P" entry of the bead dictionary object.

It is a required entry defined as part of the PDF 1.0 specification.

It contains a PageObjectElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 161, page 376.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 163, page 457.

The page entry references the page object on which this bead's rectangle is located. The page's B array must list this bead, maintaining the bidirectional page-to-bead relationship.