Journey: only split $ref->{train} if it holds a value

	# Number is either train no (ICE, RE) or line no (S, U, Bus, ...)

	# with no way of distinguishing between those

	if ( $ref->{train} ) {

		( $ref->{type}, $ref->{number} ) = split( qr{\s+}, $ref->{train} );

	}

	# The line number seems to be encoded in the trip ID

	if ( not defined $ref->{number}