 is true if the Header containing this string is present
in the request.</p>
</td>
</tr>
<tr>
<td style="white-space:nowrap">
<code>notcontains</code><br>
<em>
string
</em>
</td>
<td>
<em>(Optional)</em>
<p>NotContains is true if the Header containing this string is not present
in the request.</p>
</td>
</tr>
<tr>
<td style="white-space:nowrap">
<code>exact</code><br>
<em>
string
</em>
</td>
<td>
<em>(Optional)</em>
<p>Exact is true if the Header containing this string matches exactly
in the request.</p>
</