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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 combine_dfs(dfs, names, method):
 """Combine dataframes. Combination is either done simple by just concatenating the DataFrames or performs tracking by adding the name of the dataset as a column."""

    if method == "track":
        res = list()
        for df, identifier in zip(dfs, names):
            df["dataset"] = identifier
            res.append(df)
        return pd.concat(res, ignore_index=True)
    elif method == "simple":
        return pd.concat(dfs, ignore_index=True)