class Prawn::Table::Cell

def self.draw_cells(cells)


and content.
corresponding pt, making sure all backgrounds are behind all borders
Given an array of pairs [cell, pt], draws each cell at its 
def self.draw_cells(cells)
  cells.each do |cell, pt|
    cell.set_width_constraints
    cell.draw_background(pt)
  end
  cells.each do |cell, pt|
    cell.draw_borders(pt)
    cell.draw_bounded_content(pt)
  end
end