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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_beatmaps(self, *, since=None, beatmapset_id=None, beatmap_id=None, username=None, mode=None, include_converted=False, beatmap_hash=None, limit=500):
 """Get beatmaps. Parameters since : datetime If specified, restrict results to beatmaps *ranked* after this date. beatmapset_id If specified, restrict results to a specific beatmap set. beatmap_id If specified, restrict results to a specific beatmap. username : str or int A `str` representing the user's username, or an `int` representing the user's id. If specified, restrict results to a specific user. mode : :class:`osuapi.enums.OsuMode` If specified, restrict results to a specific osu! game mode. include_converted : bool Whether or not to include autoconverts. Defaults to false. beatmap_hash If specified, restricts results to a specific beatmap hash. limit Number of results to return. Defaults to 500, maximum 500. """

        return self._make_req(endpoints.BEATMAPS, dict(
            k=self.key,
            s=beatmapset_id,
            b=beatmap_id,
            u=username,
            since="{:%Y-%m-%d %H:%M:%S}".format(since) if since is not None else None,
            type=_username_type(username),
            m=mode.value if mode else None,
            a=int(include_converted),
            h=beatmap_hash,
            limit=limit
            ), JsonList(Beatmap))