def METHOD_NAME():
    x = np.arange(10, dtype='i4')
    y = x**2
    df1 = vaex.from_arrays(x=x, y=y, z=x+y)
    df1['z'] = df1.x + df1.z
    assert df1.fingerprint() == 'dataframe-8f2202e2b4e7845c8ace767db5a49bc4'
    df2 = vaex.from_arrays(x=x, y=y, z=x+y)
    df2['z'] = df2.x - df2.z
    assert df2.fingerprint() == 'dataframe-81043a3c5b32eaa4b18bf4a915492e23'