ass='op'>+</span> <span class='fl'>1</span><span class='op'>]</span>, collapse <span class='op'>=</span> <span class='st'>" "</span><span class='op'>)</span>
<span class='op'>}</span><span class='op'>)</span>
<span class='va'>x_test</span> <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/lapply.html'>lapply</a></span><span class='op'>(</span><span class='va'>x_test</span>, <span class='kw'>function</span><span class='op'>(</span><span class='va'>x</span><span class='op'>)</span