redef fun is_empty do return map.is_empty

	redef fun is_empty do return _the_length == 0

	# O(n) in worst case, average is O(h) with h: tree height
	#
	#     var tree = new BinTreeMap[Int, String]
	#     assert tree.is_empty
	#     tree[1] = "n1"
	#     assert not tree.is_empty
	redef fun is_empty do return root == null

	redef fun is_empty do return _items.is_empty

	# Does this file contains no properties and no sections?
	#
	# ~~~
	# var ini = new IniFile.from_string("")
	# assert ini.is_empty
	#
	# ini = new IniFile.from_string("""
	# key=value
	# """)
	# assert not ini.is_empty
	#
	# ini = new IniFile.from_string("""
	# [section]
	# """)
	# assert not ini.is_empty
	# ~~~
	redef fun is_empty do return super and sections.is_empty