code: function() {
  		
  		var self = this,
  			p = self.__options.interactive ? 'auto' : '';
  		
  		// this will be useful to know quickly if the tooltip is in
  		// the DOM or not 
  		self._$tooltip
  			.attr('id', self.__namespace)
  			.css({
  				// pointer events
  				'pointer-events': p,
  				zIndex: self.__options.zIndex
  			});
  		
  		// themes
  		// remove the old ones and add the new ones
  		$.each(self.__previousThemes, function(i, theme) {
  			self._$tooltip.removeClass(theme);
  		});
  		$.each(self.__options.theme, function(i, theme) {
  			self._$tooltip.addClass(theme);
  		});
  		
  		self.__previousThemes = $.merge([], self.__options.theme);
  		
  		return self;
  	}
docs: Do the things that need to be done only once after the tooltip
  HTML element it has been created. It has been made a separate
  method so it can be called when options are changed. Remember
  that the tooltip may actually exist in the DOM before it is
  opened, and present after it has been closed: it's the display
  plugin that takes care of handling it.
  
  @returns {self}
  @private