code: def same_column_size?(rows)
          offset = opts[:c] ? 1 : 0
          return true if rows.size == 1 + offset
          (0 + offset).upto(rows.size - 2) do |i| 
            return false unless rows[i].size == rows[i+1].size
          end
          true
        end
docs: Checks whether all rows have the same column size. Returns true if
   all columns have the same column size