Merge PR #404: [WIP] Update opamp-client module to follow style guide

Author: trask

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/OpampClientBuilder.java

@@ -34,7 +34,7 @@
  *
  * <p>Builds an {@link OpampClient} instance.
  */
-public final class OpampClientBuilder {
+public class OpampClientBuilder {
   private final Map<String, AnyValue> identifyingAttributes = new HashMap<>();
   private final Map<String, AnyValue> nonIdentifyingAttributes = new HashMap<>();
   private long capabilities = 0;

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/connectivity/http/OkHttpSender.java

@@ -18,7 +18,7 @@
 import okhttp3.RequestBody;
 import okio.BufferedSink;
 
-public final class OkHttpSender implements HttpSender {
+public class OkHttpSender implements HttpSender {
   private final OkHttpClient client;
   private final String url;
 

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/connectivity/http/RetryAfterParser.java

@@ -13,7 +13,7 @@
 import java.util.Optional;
 import java.util.regex.Pattern;
 
-public final class RetryAfterParser {
+public class RetryAfterParser {
   private final SystemTime systemTime;
   private static final Pattern SECONDS_PATTERN = Pattern.compile("\\d+");
   private static final Pattern DATE_PATTERN =

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/connectivity/websocket/OkHttpWebSocket.java

@@ -5,7 +5,8 @@
 
 package io.opentelemetry.opamp.client.internal.connectivity.websocket;
 
-import java.util.Objects;
+import static java.util.Objects.requireNonNull;
+
 import java.util.concurrent.atomic.AtomicReference;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -65,7 +66,7 @@ public void close(int code, @Nullable String reason) {
   }
 
   private okhttp3.WebSocket getWebSocket() {
-    return Objects.requireNonNull(webSocket.get());
+    return requireNonNull(webSocket.get());
   }
 
   private class ListenerAdapter extends WebSocketListener {

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/impl/OpampClientImpl.java

@@ -43,7 +43,7 @@
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
  * any time.
  */
-public final class OpampClientImpl
+public class OpampClientImpl
     implements OpampClient, ObservableState.Listener, RequestService.Callback, Supplier<Request> {
   private final RequestService requestService;
   private final AgentToServerAppenders appenders;

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/impl/OpampClientState.java

@@ -14,7 +14,7 @@
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
  * any time.
  */
-public final class OpampClientState {
+public class OpampClientState {
   public final State.RemoteConfigStatus remoteConfigStatus;
   public final State.SequenceNum sequenceNum;
   public final State.AgentDescription agentDescription;

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/impl/recipe/AgentToServerAppenders.java

@@ -23,7 +23,7 @@
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
  * any time.
  */
-public final class AgentToServerAppenders {
+public class AgentToServerAppenders {
   public final AgentDescriptionAppender agentDescriptionAppender;
   public final EffectiveConfigAppender effectiveConfigAppender;
   public final RemoteConfigStatusAppender remoteConfigStatusAppender;

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/impl/recipe/RecipeManager.java

@@ -19,7 +19,7 @@
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
  * any time.
  */
-public final class RecipeManager {
+public class RecipeManager {
   private final Object recipeLock = new Object();
   private final List<Field> constantFields;
   @Nullable private RequestRecipe previousRecipe = null;
@@ -50,7 +50,7 @@ public RecipeBuilder next() {
     }
   }
 
-  public final class RecipeBuilder {
+  public class RecipeBuilder {
     private final Set<Field> fields = new HashSet<>();
 
     @CanIgnoreReturnValue

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/impl/recipe/RequestRecipe.java

@@ -12,7 +12,7 @@
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
  * any time.
  */
-public final class RequestRecipe {
+public class RequestRecipe {
   private final Collection<Field> fields;
 
   public RequestRecipe(Collection<Field> fields) {

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/impl/recipe/appenders/AgentDescriptionAppender.java

@@ -13,7 +13,7 @@
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
  * any time.
  */
-public final class AgentDescriptionAppender implements AgentToServerAppender {
+public class AgentDescriptionAppender implements AgentToServerAppender {
   private final Supplier<AgentDescription> data;
 
   public static AgentDescriptionAppender create(Supplier<AgentDescription> data) {