Namespace Org.Apache.Pdfbox.Pdmodel.Graphics.Form Classes PDFormXObject https://www.javadoc.io/doc/org.apache.pdfbox/pdfbox/3.0.4/org/apache/pdfbox/pdmodel/graphics/form/PDFormXObject.html PDTransparencyGroup https://www.javadoc.io/doc/org.apache.pdfbox/pdfbox/3.0.4/org/apache/pdfbox/pdmodel/graphics/form/PDTransparencyGroup.html PDTransparencyGroupAttributes https://www.javadoc.io/doc/org.apache.pdfbox/pdfbox/3.0.4/org/apache/pdfbox/pdmodel/graphics/form/PDTransparencyGroupAttributes.html