def METHOD_NAME(self):
    self._filenames = []
    self._datasets = []
    self._cells = []
    self._symprecs = []
    for d in dirnames:
        dirname = os.path.join(data_dir, "data", d)
        filenames = os.listdir(dirname)
        self._filenames += [os.path.join(dirname, fname) for fname in filenames]
    for fname in self._filenames:
        cell = read_vasp(fname)
        if "distorted" in fname:
            symprec = 1e-1
        else:
            symprec = 1e-5
        self._datasets.append(get_symmetry_dataset(cell, symprec=symprec))
        self._cells.append(cell)
        self._symprecs.append(symprec)