calculate_transaction_fee (Func)

Calculate the fee for an unsigned transaction based on its mass.

PARAMETER	DESCRIPTION
network_id	The network identifier. TYPE: NetworkId
tx	The transaction to calculate fee for. TYPE: Transaction
minimum_signatures	Minimum signatures per input (default: 1). TYPE: Optional[int] DEFAULT: None

RETURNS	DESCRIPTION
Optional[int]	int | None: The fee in sompi, or None if mass exceeds limits.

RAISES	DESCRIPTION
Exception	If mass calculation fails.