How to use the pycel.excelutil.flatten function in pycel

def test_flatten():
    assert ['ddd'] == list(flatten(['ddd']))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', 1, (2, 3)]))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', (1, (2, 3))]))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', (1, 2), 3]))

    assert [None] == list(flatten(None))
    assert [True] == list(flatten(True))
    assert [1.0] == list(flatten(1.0))

def test_flatten():
    assert ['ddd'] == list(flatten(['ddd']))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', 1, (2, 3)]))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', (1, (2, 3))]))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', (1, 2), 3]))

    assert [None] == list(flatten(None))
    assert [True] == list(flatten(True))
    assert [1.0] == list(flatten(1.0))

def test_flatten():
    assert ['ddd'] == list(flatten(['ddd']))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', 1, (2, 3)]))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', (1, (2, 3))]))
    assert ['ddd', 1, 2, 3] == list(flatten(['ddd', (1, 2), 3]))

    assert [None] == list(flatten(None))
    assert [True] == list(flatten(True))
    assert [1.0] == list(flatten(1.0))

def set_value(self, address, value, set_as_range=False):
        """ Set the value of one or more cells or ranges

        :param address: `str`, `AddressRange`, `AddressCell` or a tuple, list
            or an iterable of these three
        :param value: value to set.  This can be a value or a tuple/list
            which matches the shapes needed for the given address/addresses
        :param set_as_range: With a single range address and a list like value,
            set to true to set the entire rnage to the inserted list.
        """

        if list_like(value) and not set_as_range:
            value = tuple(flatten(value))
            if list_like(address):
                address = (AddressCell(addr) for addr in flatten(address))
            else:
                address = flatten(AddressRange(address).resolve_range)
            address = tuple(address)
            assert len(address) == len(value)
            for addr, val in zip(address, value):
                self.set_value(addr, val)
            return

        elif address not in self.cell_map:
            address = AddressRange.create(address).address
            assert address in self.cell_map

        if set_as_range and list_like(value) and not (
                value and list_like(value[0])):

def cells_to_build(self, data):
        assert isinstance(data.formula, tuple)
        return zip(  # pragma: no branch
            self,  # address
            flatten(v for row in data.values for v in row),  # value
            flatten(f for row in data.formula for f in row)  # formula
        )

def concatenate(*args):
    # Excel reference: https://support.office.com/en-us/article/
    #   CONCATENATE-function-8F8AE884-2CA8-4F7A-B093-75D702BEA31D
    if tuple(flatten(args)) != args:
        return VALUE_ERROR

    error = next((x for x in args if x in ERROR_CODES), None)
    if error:
        return error

    return ''.join(coerce_to_string(a) for a in args)

def count(*args):
    # Excel reference: https://support.office.com/en-us/article/
    #   COUNT-function-a59cd7fc-b623-4d93-87a4-d23bf411294c

    return sum(1 for x in flatten(args)
               if isinstance(x, (int, float)) and not isinstance(x, bool))

error = next((i for i in flatten(args) if i in ERROR_CODES), None)
    if error:
        return error

    # verify array sizes match
    sizes = set()
    for arg in args:
        assert isinstance(arg, tuple), isinstance(arg[0], tuple)
        sizes.add((len(arg), len(arg[0])))
    if len(sizes) != 1:
        return VALUE_ERROR

    # put the values into numpy vectors
    values = np.array(tuple(tuple(
        x if isinstance(x, (float, int)) and not isinstance(x, bool) else 0
        for x in flatten(arg)) for arg in args))

    # return the sum product
    return np.sum(np.prod(values, axis=0))

""" Set the value of one or more cells or ranges

        :param address: `str`, `AddressRange`, `AddressCell` or a tuple, list
            or an iterable of these three
        :param value: value to set.  This can be a value or a tuple/list
            which matches the shapes needed for the given address/addresses
        :param set_as_range: With a single range address and a list like value,
            set to true to set the entire rnage to the inserted list.
        """

        if list_like(value) and not set_as_range:
            value = tuple(flatten(value))
            if list_like(address):
                address = (AddressCell(addr) for addr in flatten(address))
            else:
                address = flatten(AddressRange(address).resolve_range)
            address = tuple(address)
            assert len(address) == len(value)
            for addr, val in zip(address, value):
                self.set_value(addr, val)
            return

        elif address not in self.cell_map:
            address = AddressRange.create(address).address
            assert address in self.cell_map

        if set_as_range and list_like(value) and not (
                value and list_like(value[0])):
            value = (value, )

        cell_or_range = self.cell_map[address]

def _base2dec(value, base):
    value = list(flatten(value))
    if len(value) != 1 or isinstance(value[0], bool):
        return VALUE_ERROR

    value = value[0]
    if value in ERROR_CODES:
        return value

    if value in (None, EMPTY):
        value = '0'
    elif isinstance(value, (int, float)) and value >= 0:
        if int(value) == value:
            value = str(int(value))

    if isinstance(value, str) and len(value) <= 10:
        try:
            value, mask = int(value, base), _SIZE_MASK[base]