def _generate_names(cls, name):
        """Generates a series of temporary names.

        The algorithm replaces the leading characters in the name
        with ones that are valid filesystem characters, but are not
        valid package names (for both Python and pip definitions of
        package).
        """
        for i in range(1, len(name)):
            for candidate in itertools.combinations_with_replacement(
                    cls.LEADING_CHARS, i - 1):
                new_name = '~' + ''.join(candidate) + name[i:]
                if new_name != name:
                    yield new_name

        # If we make it this far, we will have to make a longer name
        for i in range(len(cls.LEADING_CHARS)):
            for candidate in itertools.combinations_with_replacement(
                    cls.LEADING_CHARS, i):
                new_name = '~' + ''.join(candidate) + name
                if new_name != name:
                    yield new_name
Generates a series of temporary names.

        The algorithm replaces the leading characters in the name
        with ones that are valid filesystem characters, but are not
        valid package names (for both Python and pip definitions of
        package).