Terminates the redirection begun by a call to Context.pushGroup() or Context.pushGroup(Content) and installs the resulting pattern as the source pattern in the given cairo context.

The behavior of this function is equivalent to the sequence of operations:

Pattern group = cr.popGroup();
cr.setSource(group);
group.dispose();

but is more convenient as their is no need for a variable to store the short-lived pointer to the pattern.

The Context.popGroup() function calls Context.restore(), (balancing a call to Context.save() by the Context.pushGroup() function), so that any changes to the graphics state will not be visible outside the group.