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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 _fetchAllChildren(self):
 """ Adds an ArrayRti per column as children so that they can be inspected easily """

        childItems = []
        if self._array.ndim == 2:
            _nRows, nCols = self._array.shape if self._array is not None else (0, 0)
            for col in range(nCols):
                colItem = SliceRti(self._array[:, col], nodeName="channel-{}".format(col),
                                   fileName=self.fileName, iconColor=self.iconColor,
                                   attributes=self.attributes)
                childItems.append(colItem)
        return childItems