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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 thermback(self):
 """Calculate thermal background count rate for ``self.obsmode``. Calculation uses :func:`~pysynphot.observationmode.ObservationMode.ThermalSpectrum` to extract thermal component source spectrum in ``photlam`` per square arcsec. Then this spectrum is integrated and multiplied by detector pixel scale and telescope collecting area to produce a count rate in count/s/pix. This unit is non-standard but used widely by STScI Exposure Time Calculator. .. note:: Similar to IRAF STSDAS SYNPHOT ``thermback`` task. Returns ------- ans : float Thermal background count rate. Raises ------ NotImplementedError Bandpass has no thermal information in graph table. """

        #The obsmode.ThermalSpectrum method will raise an exception if there is
        #no thermal information, and that will just propagate up.
        sp=self.obsmode.ThermalSpectrum()

        #Thermback is always provided in this non-standard set of units.
        #This code was copied from etc.py.
        ans = sp.integrate() * (self.obsmode.pixscale**2 *
                                self.obsmode.primary_area)
        return ans