docs: public KeysAndAttributes withKeys(java.util.Map<String, AttributeValue>... keys) {
          if (this.keys == null) {
              setKeys(new java.util.ArrayList<java.util.Map<String, AttributeValue>>(keys.length));
          }
          for (java.util.Map<String, AttributeValue> ele : keys) {
              this.keys.add(ele);
          }
          return this;
      }