def get_tags(data):
    """
    Gets all of the tags in the data

    >>> get_tags({ \
        "paths": { \
            "1": {"a": {"tags": ["c"]}, \
                  "b": {"tags": ["c"]}}, \
            "2": {"a": {"tags": ["b"]}, \
                  "d": {}}, \
            "3": {"c": {"tags": ["d", "e"]}} \
        } \
    })
    ['', 'b', 'c', 'd', 'e']
    """
    tags = set()
    for methods in data["paths"].values():
        for method in methods.values():
            if type(method) is list:
                continue
            tags |= set(method.get("tags", [""]))

    return sorted(list(tags))