code: public InstagramSubscription longitude(String longitude){
  		Preconditions.checkValidLatLong(longitude, "Invalid 'lng' key");
  		
  		this.params.put(Constants.LONGITUDE, longitude);
  		
  		return this;
  	}
docs: Configure the longitude for geography subscription
  @param longitude The longitude for geography subscription
  @return the {@link InstagramSubscription} instance for method chaining