code: public <T> T toOnlyElement(Function<? super Cursor, T> singleRowTransform, T defaultValue) {
      if (moveToFirst()) {
        return toOnlyElement(singleRowTransform);
      } else {
        close();
        return defaultValue;
      }
    }
docs: Returns the only row of this cursor transformed using the given function,
  or the supplied default value if cursor is empty.
  WARNING: This method closes cursor. Do not use this from onLoadFinished()
  
  @param singleRowTransform Function to apply on the only row of this cursor
  @param <T> Type of returned element
  @return Transformed first row of the cursor or the supplied default
  value if the cursor is empty. If the cursor contains more than one
  row, IllegalArgumentException is thrown.