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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 timeseries(datasets):
 """Expands dataset with and concats by time dimension"""

    expanded_ds = []
    for ds in datasets:
        tmp = ds.expand_dims("time")
        tmp.coords["time"] = pd.DatetimeIndex([ds.attrs["start_time"]])
        expanded_ds.append(tmp)

    res = xr.concat(expanded_ds, dim="time")
    res.attrs = combine_metadata(*[x.attrs for x in expanded_ds])
    return res