• #61: Return specific errors when trying to add non-indexable values to the sketch, including when adding NaN.
• #61: Precompute the indexable range at the mapping level rather than at the sketch level.
• #61: Allow accessing the inner DDSketch even when tracking exact summary statistics.
• #60: Improve the performance of various bin-iterating operations, including the buffered paginated store merging.
• #59: Ensure that encoding then decoding a mapping produces the exact same initial mapping.
• #58: Allow building initially non-empty sketches from provided data.
• #57: Decrease the memory footprint of the encoded buffered paginated store when possible, in the presence of buffered data.