A scrum machine, or scrummaging machine, is a padded, weighty device against which a pack of rugby football forwards can practice scrummaging and rucking. The purpose of the scrum machine is to provide teams with a safe tool with which to improve the strength and skills of their players. Using only the above description and what you know about the world, "At least one specific type of machine was successfully developed to make practicing rugby safer. " is definitely correct, incorrect, or inconclusive? 