code: function(ll, lyrs) {
          for(var lind = 0, len=lyrs.length; lind < len; lind++) {
              ll.push(lyrs[lind]);
          }
      }
docs: Method: addLayers
  Add a collection of layers to another collection of layers. Each layer in the list is tuple of
  { id, visible }.  These layer collections represent the
  /ARCXML/REQUEST/get_image/PROPERTIES/LAYERLIST/LAYERDEF items in ArcXML
  
  TODO: Add support for dynamic layer rendering.
  
  Parameters:
  ll - {Array({id,visible})} A list of layer definitions.
  lyrs - {Array({id,visible})} A list of layer definitions.