def col_regex(col, r, args, block)
        operation = "'[value]' =~ Regexp.new('#{r}')"
        pivot[r] = { col: col, operation: operation } 
      end
def col_regex(col, r, args, block)
        operation = "'[value]' =~ Regexp.new('#{r}')"
        pivot[r] = { col: col, operation: operation } 
      end
Adds a comparisson filter