docs: public void deleteCustomerSource(
              @NonNull String sourceId,
              @Nullable SourceRetrievalListener listener) {
          Map<String, Object> arguments = new HashMap<>();
          arguments.put(KEY_SOURCE, sourceId);
  
          final String operationId = UUID.randomUUID().toString();
          if (listener != null) {
              mSourceRetrievalListeners.put(operationId, listener);
          }
          mEphemeralKeyManager.retrieveEphemeralKey(operationId, ACTION_DELETE_SOURCE, arguments);
      }