f the <code>Product</code>,
<code>Field.name</code> is the declared name, <code>Field.value</code> is its value.</p><div class="fullcomment"><div class="comment cmt"><p>Allows to view a <code>Product</code> as an <code>Indexable</code>; for each declared field of the <code>Product</code>,
<code>Field.name</code> is the declared name, <code>Field.value</code> is its value.
It is recursive: <code>Indexable</code> values are converted to multiple fields; their <code>Field.name</code>s are
prefixed with the <co