An item in the store. The key must match the regex ^[A-z][A-z0-9_\.\/]{2,62}[A-z0-9]$. That
is, it must start with a letter, end with a letter or number, contain only letters, numbers,
periods, and slashes, and be between 4 and 64 characters long.
An iterator for the key-value store. Note that this protocol makes no guarantee of atomicity -
the values may change between pulls from the iterator. Unlike the Store protocol above, this
protocol is not @discoverable: it is not independently published by the component that
implements it, but rather must have one of its two protocol ends transmitted over an existing
FIDL connection.