code: boolean setSelectedSource(@NonNull String sourceId) {
          for (int i = 0; i < mCustomerSourceList.size(); i++) {
              if (sourceId.equals(mCustomerSourceList.get(i).getId())) {
                  updateSelectedIndex(i);
                  return true;
              }
          }
          return false;
      }
docs: Sets the selected source to the one whose ID is identical to the input string, if such
  a value is found.
  
  @param sourceId a stripe ID to search for among the list of {@link CustomerSource} objects
  @return {@code true} if the value was found, {@code false} if not