pub unsafe extern "C" fn btck_transaction_to_bytes(
transaction: *const btck_Transaction,
writer: btck_WriteBytes,
user_data: *mut c_void,
) -> c_intpub unsafe extern "C" fn btck_transaction_to_bytes(
transaction: *const btck_Transaction,
writer: btck_WriteBytes,
user_data: *mut c_void,
) -> c_int