code: function getAttributesForComparison( styleDefinition ) {
  		// If we have already computed it, just return it.
  		var attribs = styleDefinition._AC;
  		if ( attribs )
  			return attribs;
  
  		attribs = {};
  
  		var length = 0;
  
  		// Loop through all defined attributes.
  		var styleAttribs = styleDefinition.attributes;
  		if ( styleAttribs ) {
  			for ( var styleAtt in styleAttribs ) {
  				length++;
  				attribs[ styleAtt ] = styleAttribs[ styleAtt ];
  			}
  		}
  
  		// Includes the style definitions.
  		var styleText = CKEDITOR.style.getStyleText( styleDefinition );
  		if ( styleText ) {
  			if ( !attribs.style )
  				length++;
  			attribs.style = styleText;
  		}
  
  		// Appends the "length" information to the object.
  		attribs._length = length;
  
  		// Return it, saving it to the next request.
  		return ( styleDefinition._AC = attribs );
  	}
docs: Returns an object that can be used for style matching comparison. Attributes names and values are all lowercased, and the styles get merged with the style attribute.