You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: highlight_best_rows.m
    path of file: ./repos/toolkit-legacy/report
    
    the code of the file until where you have to start completion: function tabledata = highlight_best_rows(tabledata, columns, varargin)
% highlight_best_rows Adds highlight to the best three cells in a given
% row.
%
% The function modifies the input matrix by converting it to cell array

    
function tabledata = highlight_best_rows(tabledata, columns, varargin)
% highlight_best_rows Adds highlight to the best three cells in a given
% row.
%
% The function modifies the input matrix by converting it to cell array
% and augmenting the cells in individual columns with class labels for
% first three places acording to specified ordering. The resulting array
% can be then handed over to matrix2html function.
%
% Input:
% - tabledata (matrix): <description>
% - columns (cell): An array of strings that denote type of ordering for
% individual columns. 
%     - Decreasing: Highlight in decreasing order.
%     - Increasing: Highlight in increasing order.
%     - None: Do not highlight.
%
% Output:
% - tabledata (cell): Modified array.
%

if size(tabledata, 2) ~= numel(columns)
    error('Number of columns does not match the sorting instructuions.');
end