leaflet.js - _addItem: function(t) - checkbox - first entry - checked

maybe you would like to help me. I like to select automatically the first entry in my overlays.js ---> var labels = [];

Someone have a reason for this?

File leaflet.js / Line: 2075: t.overlay ? ((i = document.createElement("input")).type = "checkbox", i.className = "leaflet-control-layers-selector", i.defaultChecked = o) : i = this._createRadioElement("leaflet-base-layers", o), this._layerControlInputs.push(i), i.layerId = n(t.layer), mt(i, "click", this._onInputClick, this);