code: def reset ():
      
      global __all_attributes, __all_features, __implicit_features, __composite_properties
      global __subfeature_from_value, __all_top_features, __free_features
      global __all_subfeatures
  
      # sets the default value of False for each valid attribute
      for attr in VALID_ATTRIBUTES:
          setattr(Feature, attr.replace("-", "_"), False)
  
      # A map containing all features. The key is the feature name.
      # The value is an instance of Feature class.
      __all_features = {}
  
      # All non-subfeatures.
      __all_top_features = []
  
      # Maps valus to the corresponding implicit feature
      __implicit_features = {}
  
      # A map containing all composite properties. The key is a Property instance,
      # and the value is a list of Property instances
      __composite_properties = {}
  
      # Maps a value to the corresponding subfeature name.
      __subfeature_from_value = {}
  
      # All free features
      __free_features = []
  
      __all_subfeatures = []
docs: Clear the module state. This is mainly for testing purposes.