How to use the artifacts.source_type.WindowsRegistryKeySourceType function in artifacts

def testInitialize(self):
    """Tests the __init__ function."""
    source_type.WindowsRegistryKeySourceType(keys=[u'test'])

raise errors.FormatError('key_value_pairs must be a list')

    for pair in key_value_pairs:
      if not isinstance(pair, dict):
        raise errors.FormatError('key_value_pair must be a dict')

      if set(pair.keys()) != set(['key', 'value']):
        key_value_pairs = ', '.join([
            '{0:s}: {1:s}'.format(key, value) for key, value in key_value_pairs
        ])
        error_message = (
            'key_value_pair missing "key" and "value" keys, got: '
            '{0:s}').format(key_value_pairs)
        raise errors.FormatError(error_message)

      WindowsRegistryKeySourceType.ValidateKey(pair['key'])

    super(WindowsRegistryValueSourceType, self).__init__()
    self.key_value_pairs = key_value_pairs

source_type_attributes['base_object'] = self.base_object

    return source_type_attributes


class SourceTypeFactory(object):
  """Source type factory."""

  _source_type_classes = {
      definitions.TYPE_INDICATOR_ARTIFACT_GROUP: ArtifactGroupSourceType,
      definitions.TYPE_INDICATOR_COMMAND: CommandSourceType,
      definitions.TYPE_INDICATOR_DIRECTORY: DirectorySourceType,
      definitions.TYPE_INDICATOR_FILE: FileSourceType,
      definitions.TYPE_INDICATOR_PATH: PathSourceType,
      definitions.TYPE_INDICATOR_WINDOWS_REGISTRY_KEY:
          WindowsRegistryKeySourceType,
      definitions.TYPE_INDICATOR_WINDOWS_REGISTRY_VALUE:
          WindowsRegistryValueSourceType,
      definitions.TYPE_INDICATOR_WMI_QUERY: WMIQuerySourceType,
  }

  @classmethod
  def CreateSourceType(cls, type_indicator, attributes):
    """Creates a source type.

    Args:
      type_indicator (str): source type indicator.
      attributes (dict[str, object]): source type attributes.

    Returns:
      SourceType: a source type.

keys (Optional[list[str]]): key paths relative to the root of
          the Windows Registry.

    Raises:
      FormatError: when keys is not set.
    """
    if not keys:
      raise errors.FormatError('Missing keys value.')

    if not isinstance(keys, list):
      raise errors.FormatError('keys must be a list')

    for key in keys:
      self.ValidateKey(key)

    super(WindowsRegistryKeySourceType, self).__init__()
    self.keys = keys

from artifacts import errors
from artifacts import source_type


class ArtifactDefinitionsRegistry(object):
  """Artifact definitions registry."""

  _source_type_classes = {
      definitions.TYPE_INDICATOR_ARTIFACT_GROUP:
          source_type.ArtifactGroupSourceType,
      definitions.TYPE_INDICATOR_COMMAND: source_type.CommandSourceType,
      definitions.TYPE_INDICATOR_DIRECTORY: source_type.DirectorySourceType,
      definitions.TYPE_INDICATOR_FILE: source_type.FileSourceType,
      definitions.TYPE_INDICATOR_PATH: source_type.PathSourceType,
      definitions.TYPE_INDICATOR_WINDOWS_REGISTRY_KEY:
          source_type.WindowsRegistryKeySourceType,
      definitions.TYPE_INDICATOR_WINDOWS_REGISTRY_VALUE:
          source_type.WindowsRegistryValueSourceType,
      definitions.TYPE_INDICATOR_WMI_QUERY: source_type.WMIQuerySourceType,
  }

  def __init__(self):
    """Initializes an artifact definitions registry."""
    super(ArtifactDefinitionsRegistry, self).__init__()
    self._artifact_definitions = {}
    self._artifact_name_references = set()
    self._defined_artifact_names = set()

  @classmethod
  def CreateSourceType(cls, type_indicator, attributes):
    """Creates a source type object.