def validate_node(instance)
			# Ensure each parent node to this node (the goal here is to hit a question node) is valid
			!self.survey.node_maps.select { |i|
				i.node == self
			}.collect { |node_map|
				node_map.parent.node.validate_node(instance)
			}.include?(false)
		end
def validate_node(instance)
			# Ensure each parent node to this node (the goal here is to hit a question node) is valid
			!self.survey.node_maps.select { |i|
				i.node == self
			}.collect { |node_map|
				node_map.parent.node.validate_node(instance)
			}.include?(false)
		end
Answer nodes are valid if their questions are valid!
 Validate this node against an instance