Minor static analysis code fixes (#37)

Author: pankajagrawal16

src/main/java/org/apache/logging/log4j/core/layout/LambdaJsonLayout.java

@@ -39,7 +39,7 @@ public class LambdaJsonLayout extends AbstractJacksonLayout {
 
     static final String CONTENT_TYPE = "application/json";
 
-    private ObjectMapper objectMapper;
+    private final ObjectMapper objectMapper;
 
     public static class Builder<B extends Builder<B>> extends AbstractJacksonLayout.Builder<B>
             implements org.apache.logging.log4j.core.util.Builder<LambdaJsonLayout> {

src/main/java/software/amazon/lambda/logging/internal/DefaultLambdaFields.java

@@ -11,7 +11,7 @@ enum DefaultLambdaFields {
     FUNCTION_ARN("functionArn"),
     FUNCTION_MEMORY_SIZE("functionMemorySize");
 
-    private String name;
+    private final String name;
 
     DefaultLambdaFields(String name) {
         this.name = name;

src/main/java/software/amazon/lambda/logging/internal/LambdaLoggingAspect.java

@@ -34,6 +34,7 @@
 public final class LambdaLoggingAspect {
     private static final ObjectMapper mapper = new ObjectMapper();
 
+    @SuppressWarnings({"EmptyMethod", "unused"})
     @Pointcut("@annotation(powerToolsLogging)")
     public void callAt(PowerToolsLogging powerToolsLogging) {
     }

src/main/java/software/amazon/lambda/tracing/internal/LambdaTracingAspect.java

@@ -2,7 +2,6 @@
 
 import com.amazonaws.xray.AWSXRay;
 import com.amazonaws.xray.entities.Subsegment;
-import com.fasterxml.jackson.databind.ObjectMapper;
 import org.aspectj.lang.ProceedingJoinPoint;
 import org.aspectj.lang.annotation.Around;
 import org.aspectj.lang.annotation.Aspect;
@@ -18,8 +17,8 @@
 
 @Aspect
 public final class LambdaTracingAspect {
-    private static final ObjectMapper mapper = new ObjectMapper();
 
+    @SuppressWarnings({"EmptyMethod", "unused"})
     @Pointcut("@annotation(powerToolsTracing)")
     public void callAt(PowerToolsTracing powerToolsTracing) {
     }

src/test/java/software/amazon/lambda/handlers/PowerLogToolEnabled.java

@@ -14,6 +14,6 @@ public Object handleRequest(Object input, Context context) {
 
     @PowerToolsLogging
     public void anotherMethod() {
-
+        System.out.println("test");
     }
 }