ven RFC822 message stream till the
 blank line separating the header from the body. The input
 stream is left positioned at the start of the body. The
 header lines are stored internally. <p>

 For efficiency, wrap a BufferedInputStream around the actual
 input stream and pass it as the parameter. <p>

 No placeholder entries are inserted; the original order of
 the headers is preserved.</div>
<dl class="notes">
<dt>Parameters:</dt>
<dd><code>is</code> - RFC822 input stream</dd>
<dd><code>allowutf8</code> -