def __init__(self, contents: Iterable[Content] = ()) -> None:
    """Initializes the document.

    Args:
      contents: Initial contents of the document.
    """
    # TODO: b/311191572 - be more efficient if contents is a tupel iter.
    self._contents = tuple(contents)
Initializes the document.

    Args:
      contents: Initial contents of the document.
    
concordia/document/document.py