var OpenStreetMap_Mapnik = L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
    maxZoom: 19,
    attribution: '© OpenStreetMap contributors'
});
var OpenAIP = L.tileLayer('http://{s}.tile.maps.openaip.net/geowebcache/service/tms/1.0.0/openaip_basemap@EPSG%3A900913@png/{z}/{x}/{y}.{ext}', {
    attribution: 'openAIP Data (CC-BY-NC-SA)',
    ext: 'png',
    minZoom: 4,
    maxZoom: 14,
    tms: true,
    detectRetina: true,
    subdomains: '12'
});