Fee
data class FeeBumpTransactionEnvelopeXdr(val tx: FeeBumpTransactionXdr, val signatures: List<DecoratedSignatureXdr>)
XDR Source: struct FeeBumpTransactionEnvelope { FeeBumpTransaction tx; /* Each decorated signature is a signature over the SHA256 hash of * a TransactionSignaturePayload */ DecoratedSignature signatures<20>; };