Is self included (or equals) to loc?

Property definitions

nitc $ Location :: located_in
	# Is `self` included (or equals) to `loc`?
	fun located_in(loc: nullable Location): Bool do
		if loc == null then return false

		if line_start < loc.line_start then return false
		if line_start > loc.line_end then return false

		if line_end > loc.line_end then return false

		if line_start == loc.line_start then
			if column_start < loc.column_start then return false
			if line_start == loc.line_end and column_start > loc.column_end then return false
		end

		if line_end == loc.line_end and column_end > loc.column_end then return false

		return true
	end
src/location.nit:200,2--217,4