Represents the "Size" entry of the type 0 function dictionary
It is a required entry defined as part of the PDF 1.0
It contains an array which contains integers, representing PDF
Items in this array should have a minimum value of 1.
For definitive details see:.
The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 39,
The ISO PDF
Specification, ISO 32000-2:2017 PDF 2.0; Table: 39, page 124.