Openlayers 3 - add variable to ol.layer.Vector in a second time

in my project I define many var, including this one in example:

var lyr_Confini = new ol.layer.Vector({
                declutter: true,
                source: jsonSource_Confini, 
                style: style_Confini,
                interactive: true,
                title: 'Confini'
            });

In a second time, or in another file called later in the index.html, I would like to add a variable in this ol.layer.Vector without overwriting the other variables like:

permalink: 'example',

to have this example in the end:

var lyr_Confini = new ol.layer.Vector({
                    declutter: true,
                    source: jsonSource_Confini, 
                    style: style_Confini,
                    interactive: true,
                    title: 'Confini',
                    permalink: 'example',
                });

How can I do? Thanks