def _get_head_state_root(db: DatabaseAPI) -> Hash32:
try:
head_state_root = db[SchemaV1.make_head_state_root_lookup_key()]
except KeyError:
raise HeadStateSlotNotFound("No head state slot found")
return Hash32(head_state_root)
def _add_head_state_root_lookup(self, root: Hash32) -> None:
"""
Write head state root into the database.
"""
self.db.set(SchemaV1.make_head_state_root_lookup_key(), root)
