+ * Reads through the given intervals until {@code count} positions have been
+ * traversed, and returns an array consisting of two values:
+ * <ul>
+ * <li>the value at the {@code count'th} position</li>
+ * <li>+1 if the last interval read is forwards, -1 if reverse direction</li>
+ * </ul>
+ * Returns null if the ranges include less than {@code count} positions, or if
+ * {@code count < 1}.