Function cumulus_pallet_xcm::ensure_sibling_para

pub fn ensure_sibling_para<OuterOrigin>(
    o: OuterOrigin
) -> Result<ParaId, BadOrigin> where
    OuterOrigin: Into<Result<Origin, OuterOrigin>>, 

Ensure that the origin o represents a sibling parachain. Returns Ok with the parachain ID of the sibling or an Err otherwise.