message: fastfield reader fix
diff: @@ -85,24 +85,6 @@ impl<Item: FastValue> FastFieldReader<Item> {
  }
  }
  - /// Internally `multivalued` also use SingleValue Fast fields.
  - /// It works as follows... A first column contains the list of start index
  - /// for each document, a second column contains the actual values.
  - ///
  - /// The values associated to a given doc, are then
  - /// `second_column[first_column.get(doc)..first_column.get(doc+1)]`.
  - ///
  - /// Which means single value fast field reader can be indexed internally with
  - /// something different from a `DocId`. For this use case, we want to use `u64`
  - /// values.
  - ///
  - /// See `get_range` for an actual documentation about this method.
  - pub(crate) fn get_range_u64(&self, start: u64, output: &mut [Item]) -> Item {
  - for (i, out) in output.iter_mut().enumerate() {
  - *out = self.get(start + i as u32);
  - }
  - }
  -
  /// Fills an output buffer with the fast field values
  /// associated with the `DocId` going from
  /// `start` to `start + output.len()`.
  