Represents the "EF" entry of the ur transform parameters dictionary object.

It is an optional entry defined as part of the PDF 1.6 specification.

It contains an array which contains strings, representing PDF name objects.

If provided, items in this array must always take the value "shall".

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 255, page 473.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 258, page 572.

The EF (embedded files) array lists names granting rights related to embedded file attachments, such as Create to add new attachments and Import to save attachments to disk.