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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 set_thermal_background(self, T_K, nth_cc):
 """Set the properties of the background thermal plasma. **Call signature** *T_K* The temperature of the background plasma, in Kelvin. *nth_cc* The number density of thermal electrons, in cm^-3. Returns *self* for convenience in chaining. Note that the parameters set here are the same as the ones that describe the thermal electron distribution, if you choose one of the electron energy distributions that explicitly models a thermal component ("thm", "tnt", "tnp", "tng", "kappa" in the code's terminology). For the power-law-y electron distributions, these parameters are used to calculate dispersion parameters (e.g. refractive indices) and a free-free contribution, but their synchrotron contribution is ignored. """

        if not (T_K >= 0):
            raise ValueError('must have T_K >= 0; got %r' % (T_K,))
        if not (nth_cc >= 0):
            raise ValueError('must have nth_cc >= 0; got %r, %r' % (nth_cc,))

        self.in_vals[IN_VAL_T0] = T_K
        self.in_vals[IN_VAL_N0] = nth_cc
        return self