docs: def env_bool(name, truthy_values=TRUE_VALUES, required=False, default=empty):
      """Pulls an environment variable out of the environment returning it as a
      boolean. The strings ``'True'`` and ``'true'`` are the default *truthy*
      values. If not present in the environment and no default is specified,
      ``None`` is returned.
  
      :param name: The name of the environment variable be pulled
      :type name: str
  
      :param truthy_values: An iterable of values that should be considered
      truthy.
      :type truthy_values: iterable
  
      :param required: Whether the environment variable is required. If ``True``
      and the variable is not present, a ``KeyError`` is raised.
      :type required: bool
  
      :param default: The value to return if the environment variable is not
      present. (Providing a default alongside setting ``required=True`` will raise
      a ``ValueError``)
      :type default: bool
      """
      value = get_env_value(name, required=required, default=default)
      if value is empty:
          return None
      return value in TRUE_VALUES