Represents the "Changes" entry of the signature dictionary object.

It is an optional entry defined as part of the PDF 1.0 specification.

It contains an array which contains integers, representing PDF numeric objects.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 252, page 468.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 255, page 566.

The Changes array records the types of changes made to the document after the previous revision. It is an informational record of what was modified since the last signature was applied.