Wraps all word transitions with a boundary token character (\x00).
    If desired (with ``force_edges`` set to ``True``), this inserts
    the boundary character at the beginning and end of the string.

    Arguments:
    - `seq`:
    - `force_edges = True`:

def boundary_transform(seq, force_edges = True):
    '''
    Wraps all word transitions with a boundary token character (\x00).
    If desired (with ``force_edges`` set to ``True``), this inserts
    the boundary character at the beginning and end of the string.

    Arguments:
    - `seq`:
    - `force_edges = True`:
    '''
    gen = boundary_words(seq)
    if force_edges:
        gen = boundary_edges(gen)
    gen = remove_duplicates(gen)
    for char in gen:
        yield char