code: public synchronized void setLocation(GeoLocation center, double radius) {
          this.center = center;
          // convert radius to meters
          this.radius = capRadius(radius) * KILOMETER_TO_METER;
          if (this.hasListeners()) {
              this.setupQueries();
          }
      }
docs: Sets the center and radius (in kilometers) of this query, and triggers new events if necessary.
  @param center The new center
  @param radius The radius of the query, in kilometers. The maximum radius that is
  supported is about 8587km. If a radius bigger than this is passed we'll cap it.