Function compress_integer_bitpacking 

pub fn compress_integer_bitpacking(
    data: &[u8],
    num_values: usize,
    value_size: usize,
) -> CompressedChunk

Integer bitpacking compression for a batch of values. Format: [value_size: u8][num_values: u32][packed_values…] Each packed value is [used_bytes: u8][significant_bytes…]