def METHOD_NAME(T1_ns, Tphi_ns, gate_time_ns):
    val = decoherence_pauli_error(T1_ns, Tphi_ns, gate_time_ns)
    # Expected value is of the form:
    #
    #   (1/4) * [1 - e^(-t/T1)] + (1/2) * [1 - e^(-t/(2*T1) - t/Tphi]
    #
    expected_output = 0.25 * (1 - np.exp(-gate_time_ns / T1_ns)) + 0.5 * (
        1 - np.exp(-gate_time_ns * ((1 / (2 * T1_ns)) + 1 / Tphi_ns))
    )
    assert val == expected_output