This class represents a stamp object based on a page of another existing PDF document.
To avoid an unneeded overhead, the class holds the parser objects in a static variable. The class automatically only touches a single parser if different pages of a single document were needed in different stamp objects. Also internal PDF objects were shared among the stamp instances.
Some things you should keep in mind:
If you want to stamp several pages of a PDF document, you should initiate the stamp object with the biggest page number at first. This will make sure that the page tree of the original document will only be read once.
This is because the parser simply reads the page tree until it finds the needed page. This process will start at the root entry of the page tree. An example: Your first stamp is based on page 1. The lookup in the page tree will stop at page 1. After that you initiate a snd stamp which is based on page 2 the lookup will find page 1 and 2. Then you initiate a third stamp which is based on page 3 the lookup will find page 1,2 and 3. If you would start with page 3 all other pages are already known for the other stamp objects.
The stamp class will only use the content stream of a page for the appearance of the stamp. Dynamic content like links, form fields or any other annotation will not be used.
