code: public void updateCurrentCustomer(@NonNull CustomerRetrievalListener listener) {
          mCustomer = null;
  
          final String operationId = UUID.randomUUID().toString();
          mCustomerRetrievalListeners.put(operationId, listener);
          mEphemeralKeyManager.retrieveEphemeralKey(operationId, null, null);
      }
docs: Force an update of the current customer, regardless of how much time has passed.
  
  @param listener a {@link CustomerRetrievalListener} to invoke with the result of getting
  the customer from the server