def font(font, size=nil)
         style           = CharacterStyle.new
         style.font      = font
         style.font_size = size
         root.fonts << font
         if block_given?
            apply(style) {|node| yield node}
         else
            apply(style)
         end
      end
def font(font, size=nil)
         style           = CharacterStyle.new
         style.font      = font
         style.font_size = size
         root.fonts << font
         if block_given?
            apply(style) {|node| yield node}
         else
            apply(style)
         end
      end
This method provides a short cut means of creating a font command node.
 The method accepts a block that will be passed a single parameter which
 will be a reference to the font node created. After the block is
 complete the font node is appended to the end of the child nodes on the
 object that the method is called against.

 ==== Parameters
 font::  A reference to font object that represents the font to be used
         within the node.
 size::  An integer size setting for the font. Defaults to nil to
         indicate that the current font size should be used.