code: public void multiplePutEntities(String keyName1, String keyName2) {
      Datastore datastore = transaction.getDatastore();
      // [START multiplePutEntities]
      Key key1 = datastore.newKeyFactory().setKind("MyKind").newKey(keyName1);
      Entity.Builder entityBuilder1 = Entity.newBuilder(key1);
      entityBuilder1.set("propertyName", "value1");
      Entity entity1 = entityBuilder1.build();
  
      Key key2 = datastore.newKeyFactory().setKind("MyKind").newKey(keyName2);
      Entity.Builder entityBuilder2 = Entity.newBuilder(key2);
      entityBuilder2.set("propertyName", "value2");
      Entity entity2 = entityBuilder2.build();
  
      transaction.put(entity1, entity2);
      transaction.commit();
      // [END multiplePutEntities]
    }
docs: [VARIABLE "my_key_name2"]