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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 updateAssetsGrid(self):
        '''
        Updates this agent's end-of-period assets grid by constructing a multi-
        exponentially spaced grid of aXtra values.

        Parameters
        ----------
        none

        Returns
        -------
        none
        '''
        aXtraGrid = constructAssetsGrid(self)
        self.aXtraGrid = aXtraGrid
        self.addToTimeInv('aXtraGrid')