match self.input.get_slice(2) {
Some(&[0, _]) => Err(ChainError::NotSupported),
Some(&[1, _]) => Err(ChainError::NotWatched),
match self.input.get_slice(2) {
Some(&[0, _]) => Err(ChainError::NotSupported),
Some(&[1, _]) => Err(ChainError::NotWatched),