def attr_formatter(method, library)
      engine = Engine.new(library)

      #Create an instance method to do the formatting.
      define_method(method) do |spec_str|
        engine.do_format(self, spec_str)
      end

      engine
    end
def attr_formatter(method, library)
      engine = Engine.new(library)

      #Create an instance method to do the formatting.
      define_method(method) do |spec_str|
        engine.do_format(self, spec_str)
      end

      engine
    end
Define a formatter for instances of the current class.
<br>Parameters
* method - A symbol used to name the formatting method created by this method.
* library - A hash of formatting rules that define the formatting
  capabilities supported by this formatter.
<br>Meta-effects
* Creates a method (named after the symbol in method) that formats the
  instance of the class. The created method takes one parameter:
<br>Meta-method Parameters
* spec_str - A format specification string with %x etc qualifiers.
<br>Meta-method Returns
* A formatted string
<br>Returns
* The format engine used by this method.