Represents the "CL" entry of the free text annotation object.

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

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

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 174, page 396.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 177, page 481.

The callout line array contains either four (x1,y1,x2,y2) or six (x1,y1,x2,y2,x3,y3) numbers in default user space. The three-point form allows a bent callout with a knee between the annotation box and the pointed end.