docs: update mute idiom

mute-idiom/src/main/java/com/iluwatar/mute/Mute.java

@@ -26,10 +26,12 @@ package com.iluwatar.mute;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * A utility class that allows you to utilize mute idiom.
  */
+@Slf4j
 public final class Mute {
 
   // The constructor is never meant to be called.
@@ -40,7 +42,7 @@ public final class Mute {
    * Executes the <code>runnable</code> and throws the exception occurred within a {@link
    * AssertionError}. This method should be utilized to mute the operations that are guaranteed not
    * to throw an exception. For instance {@link ByteArrayOutputStream#write(byte[])} declares in
-   * it's signature that it can throw an {@link IOException}, but in reality it cannot. This is
+   * its signature that it can throw an {@link IOException}, but in reality it cannot. This is
    * because the bulk write method is not overridden in {@link ByteArrayOutputStream}.
    *
    * @param runnable a runnable that should never throw an exception on execution.

mute-idiom/src/test/java/com/iluwatar/mute/MuteTest.java

@@ -63,10 +63,9 @@ class MuteTest {
 
     Mute.loggedMute(this::methodThrowingException);
 
-    assertTrue(new String(stream.toByteArray()).contains(MESSAGE));
+    assertTrue(stream.toString().contains(MESSAGE));
   }
 
-
   private void methodNotThrowingAnyException() {
     LOGGER.info("Executed successfully");
   }