code: def load_dict(self, source, namespace=''):
          
          for key, value in source.items():
              if isinstance(key, str):
                  nskey = (namespace + '.' + key).strip('.')
                  if isinstance(value, dict):
                      self.load_dict(value, namespace=nskey)
                  else:
                      self[nskey] = value
              else:
                  raise TypeError('Key has type %r (not a string)' % type(key))
          return self
docs: Load values from a dictionary structure. Nesting can be used to
              represent namespaces.
  
              >>> c = ConfigDict()
              >>> c.load_dict({'some': {'namespace': {'key': 'value'} } })
              {'some.namespace.key': 'value'}