Represents the "Domain" entry of the type 3 shading dictionary object.

It is an optional entry defined as part of the PDF 1.0 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: 81, page 187.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 80, page 233.

The Domain array gives the parameter range for the function. At the domain minimum the first circle applies; at the maximum the second circle applies. The default is [0 1].