message: Fixed a typo on docs
diff: @@ -47,7 +47,7 @@ using <U>NSmallestVisitor</U> = NExtremumVisitor&lt;N, T, I, std::greater&lt;T&g
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  - This functor class calculates the N smallest/largest values depending on type of <I>Cmp</I> (the default is N largest) of a column. I runs in O(N*M), where N is the number of largest values and M is the total number of all values.<BR>
  + This functor class calculates the N smallest/largest values depending on type of <I>Cmp</I> (the default is N largest) of a column. It runs in O(N*M), where N is the number of largest values and M is the total number of all values.<BR>
  If N is relatively small this is better than O(M*logM). The constructor takes a single optional Boolean argument to whether skip NaN values. The default is True.<BR>
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