Clean up and clarify lambda parameters

src/test/java/net/kemitix/mon/combinator/AfterTest.java

@@ -15,7 +15,10 @@ public class AfterTest {
         //given
         final List<String> events = new ArrayList<>();
         final Function<Integer, Integer> squareDecorated =
-                After.decorate(i -> function(i, events), (v, r) -> after(v, r, events));
+                After.decorate(
+                        argument -> function(argument, events),
+                        (argument, result) -> after(argument, result, events)
+                              );
         //when
         final Integer result = squareDecorated.apply(2);
         //then
@@ -28,7 +31,7 @@ public class AfterTest {
             final Integer result,
             final List<String> events
                              ) {
-        events.add("after " + argument + " -> " + result);
+        events.add(String.format("after %d -> %d", argument, result));
     }
 
     private static Integer function(

src/test/java/net/kemitix/mon/combinator/AroundTest.java

@@ -16,7 +16,7 @@ public class AroundTest {
         final List<String> events = new ArrayList<>();
         final Function<Integer, Integer> squareDecorated =
                 Around.decorate(
-                        i -> function(i, events),
+                        argument -> function(argument, events),
                         (executable, argument) -> around(executable, argument, events)
                                );
         //when

src/test/java/net/kemitix/mon/combinator/BeforeTest.java

@@ -15,26 +15,29 @@ public class BeforeTest {
         //given
         final List<String> events = new ArrayList<>();
         final Function<Integer, Integer> squareDecorated =
-                Before.decorate(v -> before(v, events), i -> function(i, events));
+                Before.decorate(
+                        argument -> before(argument, events),
+                        argument -> function(argument, events)
+                               );
         //when
         final Integer result = squareDecorated.apply(2);
         //then
         assertThat(result).isEqualTo(4);
-        assertThat(events).containsExactly("before", "function");
+        assertThat(events).containsExactly("before 2", "function");
     }
 
     private static void before(
-            final Integer v,
+            final Integer argument,
             final List<String> events
                               ) {
-        events.add("before");
+        events.add("before " + argument);
     }
 
     private static Integer function(
-            final Integer i,
+            final Integer argument,
             final List<String> events
                                    ) {
         events.add("function");
-        return i * i;
+        return argument * argument;
     }
 }