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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 setDeclaration(self, declaration):
 """ Set the declaration this model will use for rendering the the headers. """

        assert isinstance(declaration.proxy, ProxyAbstractItemView), \
            "The model declaration must be a QtAbstractItemView subclass. " \
            "Got {]".format(declaration)

        self.declaration = declaration