class Sus::Identity

def append_unique_key(key, unique = @unique)
	if @parent
		@parent.append_unique_key(key)
	else
		key << @path
	end
	
	if unique == true
		# No key is needed because this identity is unique.
	else
		if unique
			key << unique
		elsif @line
			key << @line
		end
	end
end