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
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
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