<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def get(self, key):
    '''Return the object named by key or None if it does not exist.
    Retrieves the value from the ``child_datastore``, and de-serializes
    it on the way out.

    Args:
      key: Key naming the object to retrieve

    Returns:
      object or None
    '''

    ''''''
    value = self.child_datastore.get(key)
    return self.deserializedValue(value)