Returns distance in kilometres. (i.e. return value of 0.01 = 10m)

```
class Utils {
static getDistanceBetweenPoints(lat_1, lng_1, lat_2, lng_2) {
return (6371 *
Math.acos(
Math.cos(Math.radians(lat_1)) *
Math.cos(Math.radians(lat_2)) *
Math.cos(Math.radians(lng_2) -
Math.radians(lng_1)) +
Math.sin(Math.radians(lat_1)) *
Math.sin(Math.radians(lat_2))))
}
}
Math.radians = function (degrees) {
return degrees * Math.PI / 180
};
```