add a bit of javadoc

Author: SylvainJuge

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/IndyProxy.java

@@ -5,8 +5,16 @@
 
 package io.opentelemetry.javaagent.bootstrap;
 
+/**
+ * Interface added to indy proxies to allow unwrapping the proxy object
+ */
 public interface IndyProxy {
 
+  /**
+   * Unwraps the proxy delegate instance
+   *
+   * @return wrapped object instance
+   */
   // Method name does not fit common naming practices on purpose
   // Also, when modifying this make sure to also update string references.
   @SuppressWarnings("all")

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/IndyProxyHelper.java

@@ -9,6 +9,16 @@ public class IndyProxyHelper {
 
   private IndyProxyHelper() {}
 
+  /**
+   * Unwraps and casts an indy proxy, or just casts if it's not an indy proxy.
+   *
+   * @param <T> type of object to return
+   * @param o object to unwrap
+   * @param type expected object type
+   * @return unwrapped proxy instance or the original object (if not a proxy) cast to the expected type
+   * @throws IllegalArgumentException if the provided object the proxied object can't be cast to the expected type
+   *
+   */
   public static <T> T unwrapIfNeeded(Object o, Class<T> type) {
     if (type.isAssignableFrom(o.getClass())) {
       return type.cast(o);