add getBelow() in Matchfield - DefaultCase

src/main/java/de/tims/fleetstorm/matchfield/Matchfield.java

@@ -62,4 +62,9 @@ public class Matchfield {
 		return matchfield[center.getX()][center.getY() + 1];
 	}
 
+	public Coordinate getBelow(Coordinate center) {
+		// TODO Auto-generated method stub
+		return matchfield[center.getX()][center.getY() - 1];
+	}
+
 }

src/test/java/de/tims/fleetstorm/matchfield/MatchfieldCreationTest.java

@@ -111,4 +111,18 @@ class MatchfieldCreationTest {
 						matchfield.getField(5, 6)),
 				Arguments.of("above from (5/9) - should be null", matchfield, new Coordinate(5, 5), null));
 	}
+
+	@ParameterizedTest(name = "Get the Coordinate below")
+	@MethodSource("getCoordinateBelow")
+	void testGetBelow(String testName, Matchfield matchfield, Coordinate center, Coordinate expectedResult) {
+
+		Coordinate result = matchfield.getBelow(center);
+		assertThat(result).describedAs(testName).isEqualTo(expectedResult);
+	}
+
+	static Stream<Arguments> getCoordinateBelow() {
+		Matchfield matchfield = new Matchfield(10);
+		return Stream.of(Arguments.of("below from (5/5) - should be (5,4)", matchfield, new Coordinate(5, 5),
+				matchfield.getField(5, 4)));
+	}
 }