# File lib/backports/1.9.2/stdlib/matrix.rb, line 152
  def Matrix.rows(rows, copy = true)
    rows = convert_to_array(rows)
    rows.map! do |row|
      convert_to_array(row, copy)
    end
    size = (rows[0] || []).size
    rows.each do |row|
      Matrix.Raise ErrDimensionMismatch, "row size differs (#{row.size} should be #{size})" unless row.size == size
    end
    new rows, size
  end