Function validate_with_key 

pub fn validate_with_key<'p, 'a, V, T, R, W>(
    certificates: &'p [&'a Certificate<'a>],
    trusted_aa_ca: &'a Certificate<'a>,
    anchor_key: WorkingKey<'a>,
    context: &ValidationContext<'a, '_, V, T, R, W>,
) -> PathResult<'p, 'a, <V as Verify<W>>::Error, R::Error>
where
    W: Work,
    for<'op> V: Verify<W> + Verify<Execution<'op>, Error = <V as Verify<W>>::Error>,
    T: Watch,
    R: Recognizer<W>,

The same complete operation with an effective key supplied for the selected AA CA. Original inherited parameters are retained; a key from another SPKI refuses before control decoding or any verification callback.