if fn_arg.startswith("LDKPaymentPreimage"):
fn_arg = "uint8_t (*" + fn_arg[19:] + ")[32]"
elif fn_arg.startswith("LDKPaymentSecret"):
fn_arg = "uint8_t (*" + fn_arg[17:] + ")[32]"
elif fn_arg.startswith("LDKPaymentHash"):
fn_arg = "uint8_t (*" + fn_arg[15:] + ")[32]"
if fn_arg.startswith("LDKPaymentPreimage"):
fn_arg = "uint8_t (*" + fn_arg[19:] + ")[32]"
elif fn_arg.startswith("LDKPaymentSecret"):
fn_arg = "uint8_t (*" + fn_arg[17:] + ")[32]"
elif fn_arg.startswith("LDKPaymentHash"):
fn_arg = "uint8_t (*" + fn_arg[15:] + ")[32]"