 <span class="fl">0</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="va">out_arr</span> <span class="op">=</span> <span class="fu">replace_outside_surface</span><span class="op">(</span><span class="va">arr</span>, replace_value <span class="op">=</span> <span class="fl">0</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu">testthat</span><span class="fu">::</span><span class="fu"><a href="https://testthat.r-lib.org/reference/equality-ex