interface headers
	const clone: (self) -> (headers)
	const append: (self, string, string, boolean?) -> ()
	const each: (self) -> ((self) -> (string, string, boolean))
	const has: (self, string) -> (boolean)
	const delete: (self, string) -> (boolean)
	const geti: (self, integer) -> (string, string, boolean)
	const get_as_sequence: (self, string) -> ({"n": integer, integer:string})
	const get: (self, string) -> (string*)
	const get_comma_separated: (self, string) -> (string|nil)
	const modifyi: (self, integer, string, boolean?) -> ()
	const upsert: (self, string, string, boolean?) -> ()
	const sort: (self) -> ()
	const dump: (self, file?, string?) -> ()
end

new : () -> (headers)