void removeFromCheckpoint() {
		prevInCheckpoint.nextInCheckpoint = nextInCheckpoint;
		nextInCheckpoint.prevInCheckpoint = prevInCheckpoint;
		nextInCheckpoint = null;
		prevInCheckpoint = null;	
	}
Unlink this node from the Checkpoint list
Ghidra/Framework/DB/src/main/java/db/buffers/BufferNode.java