# Copy constructor
	init from(other: DisjointSet[E])
	do
		# Associate a root node in other to the associated root node in self
		var map = new HashMap[DisjointSetNode, DisjointSetNode]
		for e, v in other.nodes do
			# Create the associated node
			var n2 = new DisjointSetNode
			nodes[e] = n2

			# Get the root node in other and the associated one in self
			var p = other.find(e)
			var p2 = map.get_or_null(p)
			if p2 == null then
				# if no associated root node, then a new subset is created
				map[p] = n2.parent
				number_of_subsets += 1
			else
				# else attach the new node to the subset of the root node
				n2.parent = p2
			end
		end
	end