code: def pack_balance_proof_update(
          nonce: Nonce,
          balance_hash: BalanceHash,
          additional_hash: AdditionalHash,
          canonical_identifier: CanonicalIdentifier,
          partner_signature: Signature,
  ) -> bytes:
      
      return pack_balance_proof(
          nonce=nonce,
          balance_hash=balance_hash,
          additional_hash=additional_hash,
          canonical_identifier=canonical_identifier,
          msg_type=MessageTypeId.BALANCE_PROOF_UPDATE,
      ) + partner_signature
docs: Packs balance proof data to be signed for updateNonClosingBalanceProof
  
      Packs the given arguments in a byte array in the same configuration the
      contracts expect the signed data for updateNonClosingBalanceProof to have.