Function verify 

pub fn verify(
    script_pubkey: &ScriptPubkey,
    amount: Option<i64>,
    tx_to: &Transaction,
    input_index: u32,
    flags: Option<u32>,
    spent_outputs: &[TxOut],
) -> Result<(), KernelError>

Verifies a transaction input against its corresponding output script.

Arguments

• script_pubkey - The output script to verify against
• amount - Needs to be set if the segwit flag is set
• tx_to - The transaction containing the input to verify
• input_index - The index of the input within tx_to to verify
• flags - Defaults to all if none
• spent_output - The outputs being spent by this transaction

Returns

• Ok(()) if verification succeeds
• KernelError::ScriptVerify an error describing the failure