If Statement Syntax - What The 2nd Block Of Code Means?

i have the following code:

// This code is defined in one file :

editor.addMenuItem = function( name, definition )
{
if ( groupsOrder[ definition.group ] )
menuItems[ name ] = new CKEDITOR.menuItem( this, name, definition );
};

// This code is defined in another file:

if (editor.addMenuItems) {
editor.addMenuItems({
footnote : {[code]....

what the 2nd block of code means? Does it mean : If the function editor.addMenuItems exists, then call it with the following parameters?? i.e If the function exists then execute the following:

{
editor.addMenuItems({
footnote : {
label : 'Footnote',[code].....