def do_nothing(image, imagenum, new_opt, get_filename, atom1, atom2, d1, d2):
    """Explanation of the initialization function needed for methods *pull*
    and *insert* in class *COGEF*.

    This function can be used to set a cell, to set a calculator and to
    return the name of the trajectory file for the optimization.
    Do not remove accidently *FixBondLength* with *set_constraint(...)*.

    Parameters
    ----------
    image: Atoms object
        Configuration which has to be optimized.
    imagenum: int
        Image number that can be added to the name of the trajectory file.
    new_opt: bool
        Is *True* if it is a new optimization and not the restart of a
        canceled optimization. For instance, the cell need only to be set if
        *new_opt* is *True*.
    get_filename: bool
        Just return trajectory name if *get_filename* is *True*.
    atom1: int (optional)
        First atom index where force acts on.
    atom2: int (optional)
        Second atom index where force acts on.
    d1: numpy array (optional)
       Last shift vector of first atom where force acts on.
    d2: numpy array (optional)
       Last shift vector of second atom where force acts on.

    Returns
    -------
    result: str or None
        Return the name of the trajectory file only if *get_filename* is
        *True*. Add 'new forces:' in front of the file name for
        recalculating forces even if an optimization file already exists and
        seems to be converged. This can be
        useful after the change of some parameters of the calculator.
        Return 'Finished' to cancel the calculation of the COGEF path.

    """
    return None
