ONE"    NA                    </div><div class='input'><span class='fu'>to_upper_lower_case</span>(<span class='no'>strings</span>)</div><div class='output co'>#&gt; [1] "THISisAstrangeSTRING" "ANDthisANOTHERone"    NA                    </div><div class='input'><span class='fu'>to_parsed_case</span>(<span class='no'>strings</span>)</div><div class='output co'>#&gt; [1] "this_Is_a_Strange_string" "AND_THIS_ANOTHER_One"    
#&gt; [3] NA                        </div><div class='input'><span class='fu'>to_mixe