code: function(key, point) {
          if (!(point instanceof AV.GeoPoint)) {
            // Try to cast it to a GeoPoint, so that near("loc", [20,30]) works.
            point = new AV.GeoPoint(point);
          }
          this._addCondition(key, '$nearSphere', point);
          return this;
        }
docs: Add a proximity based constraint for finding objects with key point
  values near the point given.
  @param {String} key The key that the AV.GeoPoint is stored in.
  @param {AV.GeoPoint} point The reference AV.GeoPoint that is used.
  @return {AV.Query} Returns the query, so you can chain this call.