Function verify_header 

pub fn verify_header<V, H>(
    ctx: &V,
    header: &Header,
    client_id: &ClientId,
    chain_id: &ChainId,
    options: &Options,
    verifier: &impl Verifier,
) -> Result<(), ClientError>
where
    V: ExtClientValidationContext,
    ConsensusState: Convertible<<V as ClientValidationContext>::ConsensusStateRef>,
    <ConsensusState as TryFrom<<V as ClientValidationContext>::ConsensusStateRef>>::Error: Into<ClientError>,
    H: MerkleHash + Sha256 + Default,