def edges
			self.node_maps.select { |i| !i.marked_for_destruction? }.select { |i|
				i.node && i.parent
			}.collect { |i|
				{
					:source => i.parent.node.id,
					:target => i.node.id,
				}
			}.uniq
		end
def edges
			self.node_maps.select { |i| !i.marked_for_destruction? }.select { |i|
				i.node && i.parent
			}.collect { |i|
				{
					:source => i.parent.node.id,
					:target => i.node.id,
				}
			}.uniq
		end
All the connective edges