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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 add(self, order, cells, no_validation=False):
 """Add cells at a given order to the MOC. The cells are inserted into the MOC at the specified order. This leaves the MOC in an un-normalized state. The cells are given as a collection of integers (or types which can be converted to integers). 2 4 The `no_validation` option can be given to skip validation of the cell numbers. They must already be integers in the correct range. """


        self._normalized = False

        order = self._validate_order(order)

        if no_validation:
            # Simply add the given cells to the set with no validation.
            self._orders[order].update(cells)

        else:
            # Collect validated cell numbers in a set for addition.
            cell_set = set()

            for cell in cells:
                cell = self._validate_cell(order, cell)
                cell_set.add(cell)

            self._orders[order].update(cell_set)