Use @NonNullApi to explicitly reflect non-null return types and params by default

ebean-test/src/test/java/io/ebeaninternal/api/TDSpiEbeanServer.java

@@ -1,5 +1,6 @@
 package io.ebeaninternal.api;
 
+import io.avaje.lang.NonNullApi;
 import io.ebean.*;
 import io.ebean.annotation.Platform;
 import io.ebean.annotation.TxIsolation;
@@ -37,6 +38,7 @@ import java.util.stream.Stream;
 /**
  * Test double for SpiEbeanServer.
  */
+@NonNullApi
 public class TDSpiEbeanServer extends TDSpiServer implements SpiEbeanServer {
 
   String name;

ebean-test/src/test/java/io/ebeaninternal/api/TDSpiServer.java

@@ -1,5 +1,6 @@
 package io.ebeaninternal.api;
 
+import io.avaje.lang.NonNullApi;
 import io.ebean.*;
 import io.ebean.annotation.Platform;
 import io.ebean.annotation.TxIsolation;
@@ -25,6 +26,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.Callable;
 
+@NonNullApi
 public class TDSpiServer implements SpiServer {
   @Override
   public void shutdown() {

ebean-test/src/test/java/io/ebeaninternal/server/cluster/binarymessage/BinaryTransactionEventReadWriteTest.java

@@ -15,6 +15,7 @@ import io.ebeaninternal.server.transaction.RemoteTransactionEvent;
 import org.junit.jupiter.api.Test;
 import org.tests.model.basic.Customer;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.HashSet;
@@ -99,8 +100,9 @@ public class BinaryTransactionEventReadWriteTest extends BaseTestCase {
   }
 
   class TDEbeanServer extends TDSpiEbeanServer {
+    @Nonnull
     @Override
-    public BeanDescriptor<?> descriptorById(String descriptorId) {
+    public BeanDescriptor<?> descriptorById(@Nonnull String descriptorId) {
       return customerBeanDescriptor;
     }
   }