Returns all input files as a dict of {filename: vasp object}

        Returns:
            dict of {filename: object}, e.g., {'INCAR': Incar object, ...}

def all_input(self):
        """
        Returns all input files as a dict of {filename: vasp object}

        Returns:
            dict of {filename: object}, e.g., {'INCAR': Incar object, ...}
        """
        return {'INCAR': self.incar,
                'KPOINTS': self.kpoints,
                'POSCAR': self.poscar,
                'POTCAR': self.potcar}