Represents the "NumCopies" entry of the viewer preferences dictionary object.

It is an optional entry defined as part of the PDF 1.7 specification.

It contains an integer representing a PDF numeric object.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 150, page 365.

Adobe Supplement to the ISO 32000, BaseVersion: 1.7, ExtensionLevel: 3; Table: 8.1, page 28.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 147, page 437.