def METHOD_NAME(self, header_hashes: List[bytes32]) -> Set[bytes32]:
    """
    Returns: peer ids of peers that have at least one of the header hashes.
    """
    node_ids: Set[bytes32] = set()
    for header_hash in header_hashes:
        if header_hash in self.peak_to_peer:
            for node_id in self.peak_to_peer[header_hash]:
                node_ids.add(node_id)
    return node_ids