pan class="op">)</span><span class="op">)</span>
<span class="co"># [&lt;#&gt; Error in py_call_impl(callable, dots$args, dots$keywords): InvalidArgumentError: assertion failed: </span>
<span class="co"># [&lt;Assert condition R expression&gt;: `x &gt; 0`] [x is positive] [`x` value:] [-1] </span>
<span class="co"># [&lt;R call stack&gt;:] </span>
<span class="co"># [&lt;R call 1&gt;: tf_assert(x &gt; 0, \"x is positive\")] </span>
<span class="co"># [&lt;R call 2&gt;: (function (x) ] </span>
<span class="c