examples/Leaflet.PolarMap/shapefiles/demo.js
function (featureData, layer) {
      var bbox = featureData.geometry.bbox;
      var llBounds = L.latLngBounds([bbox[1], bbox[0]], [bbox[3], bbox[2]]);
      return boundsLimit.contains(llBounds);
    }
function (featureData, layer) {
      var bbox = featureData.geometry.bbox;
      var llBounds = L.latLngBounds([bbox[1], bbox[0]], [bbox[3], bbox[2]]);
      return boundsLimit.contains(llBounds);
    }
avoid loading features South of 45N. Errors will occur when loading Antarctic data.