Method: Set the visibility of the successive elements.

Method: Add transparency parameters to the current extgstate

Method: Add an extgstate

Method: Put extgstates for object transparency

Method: Set alpha for stroking (CA) and non-stroking (ca) operations.

Method: Set the default JPEG compression quality (1-100)

Method: Create a new page group.

Method: Return the alias for the total number of pages in the current page group.

Method: Return the current page in the group.

Method: Put pdf layers.