and the m--'

  But here, to Alice's great surprise, the Duchess's voice died
away, even in the middle of her favourite word `moral,' and the
arm that was linked into hers began to tremble.  Alice looked up,
and there stood the Queen in front of them, with her arms folded,
frowning like a thunderstorm.

  `A fine day, your Majesty!' the Duchess began in a low, weak
voice.

       * in that case, getProperty *will* return null.
       *
       * TODO(b/192002623): Handle that case: Either:
       *
       * - Skip non-string keys and values entirely, as proposed in the linked bug.
       *
       * - Throw ClassCastException instead of NullPointerException, as documented in the current
       *   Javadoc. (Note that we can't necessarily "just" change our call to `getProperty` to `get`

       * in that case, getProperty *will* return null.
       *
       * TODO(b/192002623): Handle that case: Either:
       *
       * - Skip non-string keys and values entirely, as proposed in the linked bug.
       *
       * - Throw ClassCastException instead of NullPointerException, as documented in the current
       *   Javadoc. (Note that we can't necessarily "just" change our call to `getProperty` to `get`