/code> - value must fulfil this predicate.</dd>
<dt>Returns:</dt>
<dd><code>true</code> if and only if a header with the given name exists, having either a whitespace-trimmed value
 matching the predicate, or having at least one whitespace-trimmed single value in a token-separated list of single values.</dd>
<dt>Since:</dt>
<dd>4.0</dd>
<dt>See Also:</dt>
<dd>
<ul class="tag-list">
<li><a href="#getHeaders()"><code>getHeaders()</code></a></li>
<li><a href="#getHeaderString(java.lang.String)"><code>getHeader