Verify a Merkle Audit Path.

        See section 2.1.1 of RFC6962 for the exact path description.

        Args:
            leaf: The leaf for which the proof was provided.
            leaf_index: Index of the leaf in the tree.
            proof: A list of SHA-256 hashes representing the  Merkle audit
            path.
            sth: STH with the same tree size as the one used to fetch the
            proof.
            The sha256_root_hash from this STH will be compared against the
            root hash produced from the proof.

        Returns:
            True. The return value is enforced by a decorator and need not be
                checked by the caller.

        Raises:
            ProofError: the proof is invalid.

def verify_leaf_inclusion(self, leaf: bytes, leaf_index: int,
                              proof: List[bytes], sth: STH):
        """Verify a Merkle Audit Path.

        See section 2.1.1 of RFC6962 for the exact path description.

        Args:
            leaf: The leaf for which the proof was provided.
            leaf_index: Index of the leaf in the tree.
            proof: A list of SHA-256 hashes representing the  Merkle audit
            path.
            sth: STH with the same tree size as the one used to fetch the
            proof.
            The sha256_root_hash from this STH will be compared against the
            root hash produced from the proof.

        Returns:
            True. The return value is enforced by a decorator and need not be
                checked by the caller.

        Raises:
            ProofError: the proof is invalid.
        """
        leaf_hash = self.hasher.hash_leaf(leaf)
        return self.verify_leaf_hash_inclusion(leaf_hash, leaf_index, proof,
                                               sth)