code: public void detachPaymentMethod(
              @NonNull String paymentMethodId,
              @Nullable PaymentMethodRetrievalListener listener) {
          Map<String, Object> arguments = new HashMap<>();
          arguments.put(KEY_PAYMENT_METHOD, paymentMethodId);
  
          final String operationId = UUID.randomUUID().toString();
          if (listener != null) {
              mPaymentMethodRetrievalListeners.put(operationId, listener);
          }
          mEphemeralKeyManager
                  .retrieveEphemeralKey(operationId, ACTION_DETACH_PAYMENT_METHOD, arguments);
      }
docs: Detaches a PaymentMethod from a Customer.
  
  @param paymentMethodId the ID of the payment method to be detached
  @param listener        a {@link PaymentMethodRetrievalListener} to be notified when the
  api call is complete. The api call will return the removed source.