code: def col_positions(pos, cols)
          if pos.nil? || pos.empty?
            pos = []
            cols.each { |c| pos << Array.new(c.size) { |c| c } }
            pos
          else
            pos.split(';').collect { |p| p.split(',').collect { |p| p.to_i } }
          end
        end
docs: Initializes the column positions where the source file columns have to
   be inserted. If no column positions are provided the inserted columns
   are put at the beginning of the row