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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 _to_dict_fixed_width_arrays(self, var_len_str=True):
 """A dict of arrays that stores data and annotation. It is sufficient for reconstructing the object. """

        self.strings_to_categoricals()
        obs_rec, uns_obs = df_to_records_fixed_width(self._obs, var_len_str)
        var_rec, uns_var = df_to_records_fixed_width(self._var, var_len_str)
        layers = self.layers.as_dict()
        d = {
            'X': self._X,
            'obs': obs_rec,
            'var': var_rec,
            'obsm': self._obsm,
            'varm': self._varm,
            'layers': layers,
            # add the categories to the unstructured annotation
            'uns': {**self._uns, **uns_obs, **uns_var}}

        if self.raw is not None:
            self.strings_to_categoricals(self.raw._var)
            var_rec, uns_var = df_to_records_fixed_width(self.raw._var, var_len_str)
            d['raw.X'] = self.raw.X
            d['raw.var'] = var_rec
            d['raw.varm'] = self.raw.varm
            d['raw.cat'] = uns_var

        return d