def METHOD_NAME(z: complex) -> complex:
    """Convert parallel impedance to serial impedance equivalent"""
    z_sq_sum = z.real**2 + z.imag**2 or 10.0e-30
    return complex(
        z.real * z.imag**2 / z_sq_sum, z.real**2 * z.imag / z_sq_sum
    )