buffer object's data store with data from client
            memory.
        </p>
        <p>
            <em class="parameter"><code>offset</code></em> and <em class="parameter"><code>size</code></em>
            specify the extent of the region within the data store of the
            buffer object to fill with data. Data, initially supplied in a
            format specified by <em class="parameter"><code>format</code></em> in data type
            <em class="parameter"><code>type</code></em> is read from