# Is the production contained in full block of line?
	# Computed by `parentize_tokens`
	fun is_block: Bool
	do
		if first_token == null or last_token == null then return false
		#sys.stderr.write "{self}@{location}: start={first_token.is_starting_line} {first_token.inspect}@{first_token.location} ; end={last_token.is_ending_line} {last_token.inspect}@{last_token.location}\n"
		return first_token.is_starting_line and last_token.is_ending_line
	end