docs: update poison pill

poison-pill/src/test/java/com/iluwatar/poison/pill/ConsumerTest.java

@@ -92,7 +92,7 @@ class ConsumerTest {
     return msg;
   }
 
-  private class InMemoryAppender extends AppenderBase<ILoggingEvent> {
+  private static class InMemoryAppender extends AppenderBase<ILoggingEvent> {
     private final List<ILoggingEvent> log = new LinkedList<>();
 
     public InMemoryAppender(Class clazz) {

poison-pill/src/test/java/com/iluwatar/poison/pill/PoisonMessageTest.java

@@ -39,16 +39,12 @@ class PoisonMessageTest {
 
   @Test
   void testAddHeader() {
-    assertThrows(UnsupportedOperationException.class, () -> {
-      POISON_PILL.addHeader(Headers.SENDER, "sender");
-    });
+    assertThrows(UnsupportedOperationException.class, () -> POISON_PILL.addHeader(Headers.SENDER, "sender"));
   }
 
   @Test
   void testGetHeader() {
-    assertThrows(UnsupportedOperationException.class, () -> {
-      POISON_PILL.getHeader(Headers.SENDER);
-    });
+    assertThrows(UnsupportedOperationException.class, () -> POISON_PILL.getHeader(Headers.SENDER));
   }
 
   @Test
@@ -58,9 +54,7 @@ class PoisonMessageTest {
 
   @Test
   void testSetBody() {
-    assertThrows(UnsupportedOperationException.class, () -> {
-      POISON_PILL.setBody("Test message.");
-    });
+    assertThrows(UnsupportedOperationException.class, () -> POISON_PILL.setBody("Test message."));
   }
 
   @Test

poison-pill/src/test/java/com/iluwatar/poison/pill/SimpleMessageTest.java

@@ -56,10 +56,6 @@ class SimpleMessageTest {
   void testUnModifiableHeaders() {
     final var message = new SimpleMessage();
     final var headers = message.getHeaders();
-    assertThrows(UnsupportedOperationException.class, () -> {
-      headers.put(Message.Headers.SENDER, "test");
-    });
+    assertThrows(UnsupportedOperationException.class, () -> headers.put(Message.Headers.SENDER, "test"));
   }
-
-
 }