public PlaceAutocompleteRequest radius(int radius) {
    return param("radius", String.valueOf(radius));
  }
The distance (in meters) within which to return place results. Note that setting a radius
biases results to the indicated area, but may not fully restrict results to the specified area.

@param radius The radius over which to bias results.
@return Returns this {@code PlaceAutocompleteRequest} for call chaining.
src/main/java/com/google/maps/PlaceAutocompleteRequest.java