Add debugging for oving5

src/main/java/oving5/debugging/StringMergingIterator.java

@@ -0,0 +1,47 @@
+package oving5.debugging;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+public class StringMergingIterator implements Iterator<String> {
+
+	private final Iterator<String> first;
+	private final Iterator<String> second;
+	private boolean turnSwitch = true;
+
+	public StringMergingIterator(Iterator<String> first, Iterator<String> second) {
+		this.first = first;
+		this.second = second;
+	}
+
+	@Override
+	public boolean hasNext() {
+		return this.first.hasNext() || this.second.hasNext();
+	}
+
+	@Override
+	public String next() {
+		if (!this.hasNext()) {
+			throw new NoSuchElementException();
+		}
+
+		String result = null;
+
+		if (!this.first.hasNext()) {
+			result = this.first.next();
+		} else if (!this.second.hasNext()) {
+			result = this.second.next();
+		} else {
+			if (this.turnSwitch) {
+				result = this.first.next();
+				this.turnSwitch = false;
+			}
+			if (!this.turnSwitch) {
+				result = this.second.next();
+				this.turnSwitch = true;
+			}
+		}
+
+		return result;
+	}
+}