code: public InstagramSubscription clientSecret(String clientSecret) {
  		Preconditions.checkEmptyString(clientSecret, "Invalid 'clientSecret' key");
  
  		this.params.put(Constants.CLIENT_SECRET, clientSecret);
  		
  		return this;
  	}
docs: Configure the clientSecret
  @param clientSecret The clientSecret for your application
  @return the {@link InstagramSubscription} instance for method chaining