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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 _update_srcmap(self, name, src, **kwargs):
 """Update the source map for an existing source in memory."""


        k = self._create_srcmap(name, src, **kwargs)
        scale = self._src_expscale.get(name, 1.0)
        k *= scale

        # Force the source map to be cached
        # FIXME: No longer necessary to force cacheing in ST after 11-05-02
        self.like.logLike.sourceMap(str(name)).model()
        self.like.logLike.setSourceMapImage(str(name), np.ravel(k))
        self.like.logLike.sourceMap(str(name)).model()

        normPar = self.like.normPar(name)        
        if not normPar.isFree():
            self.like.logLike.buildFixedModelWts()