Override the default array allocation to produce a LabelArray when we
        have a string-like dtype.

def _allocate_output(self, windows, shape):
        """
        Override the default array allocation to produce a LabelArray when we
        have a string-like dtype.
        """
        if self.dtype == int64_dtype:
            return super(CustomClassifier, self)._allocate_output(
                windows,
                shape,
            )

        # This is a little bit of a hack.  We might not know what the
        # categories for a LabelArray are until it's actually been loaded, so
        # we need to look at the underlying data.
        return windows[0].data.empty_like(shape)