Function mpt_issuance_keylet 

pub unsafe fn mpt_issuance_keylet(
    _issuer_ptr: *const u8,
    _issuer_len: usize,
    _sequence_ptr: *const u8,
    _sequence_len: usize,
    _out_buff_ptr: *mut u8,
    _out_buff_len: usize,
) -> i32