'Return a value from the container or None if the value is not set.
:param key: a string using dotted notation for nested dictionary
lookups'

def get(self, key):

    self.inspect_if_not_inspected()
    def get_value(dictionary, key):
        return (dictionary or {}).get(key)
    return reduce(get_value, key.split(u'.'), self.dictionary)
