Represents the "WC" entry of the document catalog additional-actions dictionary object.

It is an optional entry defined as part of the PDF 1.4 specification.

It contains a JavaScriptActionElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 197, page 417.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 200, page 505.

The will-close action fires before the viewer closes the document. JavaScript in this action can perform final validation, log activity, or prompt the user to confirm closure.