    <code class="constant">GL_INVALID_ENUM</code> is generated by
            <code class="function">glUnmapBuffer</code> if
            <em class="parameter"><code>target</code></em> is not one of the buffer binding
            targets listed above.
        </p>
        <p>
            <code class="constant">GL_INVALID_OPERATION</code> is generated by
            <code class="function">glUnmapBuffer</code> if zero is bound to
            <em class="parameter"><code>target</code></em>.
        </p>
        