Function encode_legacy_lookup_empty 

pub fn encode_legacy_lookup_empty() -> Bytes

ABI-encode legacyLookupMessageBatchProof’s all-zero 9-value tuple. The head is nine words (0x120), so the empty proof array begins at 0x120 and the empty calldataForL1 at 0x140; both length words live inside the 0x160 buffer.