def list_item(name, identifier={:index => 0}, &block)
      standard_methods(name, identifier, 'list_item_for', &block)
      define_method(name) do
        return platform.list_item_text_for identifier.clone unless block_given?
        self.send("#{name}_element").text
      end
    end
def list_item(name, identifier={:index => 0}, &block)
      standard_methods(name, identifier, 'list_item_for', &block)
      define_method(name) do
        return platform.list_item_text_for identifier.clone unless block_given?
        self.send("#{name}_element").text
      end
    end
adds three methods - one to retrieve the text from a list item,
 another to return the list item element, and another to check the list item's
 existence.

 @example
   list_item(:item_one, :id => 'one')
   # will generate 'item_one', 'item_one_element', and 'item_one?' methods

 @param [Symbol] the name used for the generated methods
 @param [Hash] identifier how we find a list item.
 @param optional block to be invoked when element method is called