def align_column n, alignment
      r = rows
      column(n).each_with_index do |col, i|
        cell = r[i][n]
        next unless cell
        cell.alignment = alignment unless cell.alignment?
      end
    end
def align_column n, alignment
      r = rows
      column(n).each_with_index do |col, i|
        cell = r[i][n]
        next unless cell
        cell.alignment = alignment unless cell.alignment?
      end
    end
Generates a ASCII table with the given _options_.

 Align column _n_ to the given _alignment_ of :center, :left, or :right.