Is self an orphan line (blank before and after)?

Property definitions

nitc :: pretty $ TComment :: is_orphan
	# Is `self` an orphan line (blank before and after)?
	private fun is_orphan: Bool do
		return prev_token isa TEol and
		   (prev_token.prev_token isa TEol or prev_token.prev_token isa TComment) and
		   next_token isa TEol
	end
src/pretty.nit:472,2--477,4