code: public KeysAndAttributes withKeys(Key... keys) {
          if (getKeys() == null) setKeys(new java.util.ArrayList<Key>(keys.length));
          for (Key value : keys) {
              getKeys().add(value);
          }
          return this;
      }
docs: Sets the value of the Keys property for this object.
  <p>
  Returns a reference to this object so that method calls can be chained together.
  <p>
  <b>Constraints:</b><br/>
  <b>Length: </b>1 - 100<br/>
  
  @param keys The new value for the Keys property for this object.
  
  @return A reference to this updated object so that method calls can be chained
  together.