Function iter_key_block_entry_types 

pub(crate) fn iter_key_block_entry_types(
    header: KeyBlockHeader,
    block: &[u8],
) -> impl Iterator<Item = u8> + '_

Iterates over entry type bytes in a key block.

For variable-size key blocks, reads byte 0 of each 4-byte offset table entry. For fixed-size key blocks, yields the single value_type repeated entry_count times.