code: public @Nullable
      Snackbar remove(Set<Integer> positions) {
          if (mSnackBar == null) {
              return null;
          }
  
          View snackbarView = mSnackBar.getView();
          TextView snackbarText = (TextView) snackbarView.findViewById(com.google.android.material.R.id.snackbar_text);
  
          return remove(snackbarView, snackbarText.getText().toString(), mSnackbarActionText, mSnackBar.getDuration(), positions);
      }
docs: convenience method to be used if you have previously set a {@link Snackbar} with {@link #withSnackBar(Snackbar, String)}
  
  @param positions the positions where the items were removed
  @return the snackbar or null if {@link #withSnackBar(Snackbar, String)} was not previously called