@Override
	protected GffMarker readNext() {
		// Try to read a line
		try {
			while (ready()) {
				line = readLine();
				if (line == null) return null; // End of file?

				// Parse line
				GffMarker seqChange = parse(line);
				if (seqChange != null) return seqChange;

			}
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
		return null;
	}