def METHOD_NAME():
    """
    We first perform concatenation of two dataframes,
    then drop duplicates.
    Resulting dataframe must be equal to the union of the two original dataframe
    """
    env: cy.CylonEnv = cy.CylonEnv(config=cy.MPIConfig(), distributed=True)
    print("CylonEnv Initialized: My rank: ", env.rank)
    inputFile1 = "data/input/cities_a_" + str(env.rank) + ".csv"
    inputFile2 = "data/input/cities_b_" + str(env.rank) + ".csv"
    unionFile = "data/output/union_cities_" + str(env.rank) + ".csv"
    df1 = gcy.DataFrame.from_cudf(cudf.read_csv(inputFile1))
    df2 = gcy.DataFrame.from_cudf(cudf.read_csv(inputFile2))
    concatedDf = gcy.concat([df1, df2], env=env)
    duplicates_dropped = concatedDf.drop_duplicates(ignore_index=True, env=env)
    d_dropped_sorted = duplicates_dropped.to_cudf().sort_values(by=["city", "state_id"], ignore_index=True)
    saved_union = cudf.read_csv(unionFile).sort_values(by=["city", "state_id"], ignore_index=True)
    assert d_dropped_sorted.equals(saved_union), \
        "Duplicates dropped DataFrame and the DataFrame from file are not equal"