an> (<span class="mdzsyn-coresym">fn</span> [<span class="mdzsyn-symbol">self</span> <span class="mdzsyn-symbol">x</span>] (<span class="mdzsyn-coresym">print</span> <span class="mdzsyn-string">"behaving "</span> <span class="mdzsyn-symbol">x</span>))})
(<span class="mdzsyn-coresym">def</span> <span class="mdzsyn-symbol">proto2</span> @{<span class="mdzsyn-keyword">:type</span> <span class="mdzsyn-keyword">:custom2</span>
              <span class="mdzsyn-keyword">:behave</span> (<span class="mdzsyn-coresym