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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 Field(self, field, Value = None):
        '''
        Add field to bitmap
        '''
        if Value == None:
            try:
                return self.__Bitmap[field]
            except KeyError:
                return None
        elif Value == 1 or Value == 0:
            self.__Bitmap[field] = Value
        else:
            raise ValueError