def calculate_hash(self):
concated = ''
for a_child in self.children:
if a_child is not None:
if a_child.get_hash is None:
a_child.calculate_hash()
concated += a_child.get_hash
self.hash = Util.get_hash(concated)
def calculate_hash(self):
self.hash = Util.get_hash(self.data)
