lly empty.
   The <code class="code">n</code> parameter is the initial size of the internal byte sequence
   that holds the buffer contents. That byte sequence is automatically
   reallocated when more than <code class="code">n</code> characters are stored in the buffer,
   but shrinks back to <code class="code">n</code> characters when <code class="code">reset</code> is called.
   For best performance, <code class="code">n</code> should be of the same order of magnitude
   as the number of characters that 