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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_array_items_description(item: Array) -> str: """Returns a description for an array's items. :param item: The Array type whose items should be documented. :returns: A string documenting what type the array's items should be. """

    desc = ''
    if isinstance(item.items, list):
        # This means the type has a list of types where each position is
        # mapped to a different type.  Document what each type should be.
        desc = ''
        item_pos_template = (
            ' *Item {pos} must be*: {description}{enum}{ref}')
        for pos, item in enumerate(item.items):
            _enum = ''
            ref = ''
            if issubclass(item, Enum):
                _enum = ' Must be one of: `{}`'.format(item.enum)
                if item.case_insensitive:
                    _enum += ' (case-insensitive)'
                _enum += '.'
            elif issubclass(item, Object):
                ref = get_object_reference(item)

            desc += item_pos_template.format(
                pos=pos, description=item.description, enum=_enum,
                ref=ref)

    else:
        # Otherwise just document the type assigned to `items`.
        desc = item.items.description
        _enum = ''
        ref = ''
        if issubclass(item.items, Enum):
            _enum = ' Must be one of: `{}`'.format(
                item.items.enum)
            if item.items.case_insensitive:
                _enum += ' (case-insensitive)'
            _enum += '.'
        elif issubclass(item.items, Object):
            ref = get_object_reference(item.items)
        desc = '  *Items must be*: {description}{enum}{ref}'.format(
            description=desc, enum=_enum, ref=ref)
    return desc