def shading_colour(colour)
         if block_given?
            0.upto(self.size - 1) do |x|
               row = self[x]
               0.upto(row.size - 1) do |y|
                  apply = yield row[y], x, y
                  row[y].shading_colour = colour if apply
               end
            end
         end
      end
def shading_colour(colour)
         if block_given?
            0.upto(self.size - 1) do |x|
               row = self[x]
               0.upto(row.size - 1) do |y|
                  apply = yield row[y], x, y
                  row[y].shading_colour = colour if apply
               end
            end
         end
      end
def shading_colour ( colour ) if block_given? 0 . upto ( self . size - 1 ) do | x | row = self [ x ] 0 . upto ( row . size - 1 ) do | y | apply = yield row [ y ] , x , y row [ y ] . shading_colour = colour if apply end end end end
This method provides a means of assigning a shading colour to a
 selection of cells within a table. The method accepts a block that
 takes three parameters - a TableCellNode representing a cell within the
 table, an integer representing the x offset of the cell and an integer
 representing the y offset of the cell. If the block returns true then
 shading will be applied to the cell.

 ==== Parameters
 colour::  A reference to a Colour object representing the shading colour
           to be applied. Set to nil to remove shading.
This method provides a means of assigning a shading colour to a selection of cells within a table . The method accepts a block that takes three parameters - a TableCellNode representing a cell within the table an integer representing the x offset of the cell and an integer representing the y offset of the cell . If the block returns true then shading will be applied to the cell .