def setup(self):
        """
        Performs initial setup for VaspJob, including overriding any settings
        and backing up.
        """
        decompress_dir('.')

        if self.backup:
            for f in VASP_INPUT_FILES:
                shutil.copy(f, "{}.orig".format(f))

        if self.auto_npar:
            try:
                incar = Incar.from_file("INCAR")
                # Only optimized NPAR for non-HF and non-RPA calculations.
                if not (incar.get("LHFCALC") or incar.get("LRPA") or
                        incar.get("LEPSILON")):
                    if incar.get("IBRION") in [5, 6, 7, 8]:
                        # NPAR should not be set for Hessian matrix
                        # calculations, whether in DFPT or otherwise.
                        del incar["NPAR"]
                    else:
                        import multiprocessing
                        # try sge environment variable first
                        # (since multiprocessing counts cores on the current
                        # machine only)
                        ncores = os.environ.get('NSLOTS') or \
                            multiprocessing.cpu_count()
                        ncores = int(ncores)
                        for npar in range(int(math.sqrt(ncores)),
                                          ncores):
                            if ncores % npar == 0:
                                incar["NPAR"] = npar
                                break
                    incar.write_file("INCAR")
            except:
                pass

        if self.auto_continue:
            if os.path.exists("continue.json"):
                actions = loadfn("continue.json").get("actions")
                logger.info("Continuing previous VaspJob. Actions: {}".format(actions))
                backup(VASP_BACKUP_FILES, prefix="prev_run")
                VaspModder().apply_actions(actions)

            else:
                # Default functionality is to copy CONTCAR to POSCAR and set
                # ISTART to 1 in the INCAR, but other actions can be specified
                if self.auto_continue is True:
                    actions = [{"file": "CONTCAR",
                                "action": {"_file_copy": {"dest": "POSCAR"}}},
                               {"dict": "INCAR",
                                "action": {"_set": {"ISTART": 1}}}]
                else:
                    actions = self.auto_continue
                dumpfn({"actions": actions}, "continue.json")

        if self.settings_override is not None:
            VaspModder().apply_actions(self.settings_override)
Performs initial setup for VaspJob, including overriding any settings
        and backing up.