
"""
`Basics.modify()`  ... modifies some data, either interactively or due to some given rule.

  + `("level energies: interactive", multiplet::Multiplet)`  
    ... to shift the total energies of the atomic levels in multiplet interactively; a (new) multiplet::Multiplet is 
        returned in which the total energies are just modified accordingly. **Not yet implemented !**
"""
function Basics.modify(sa::String, multiplet::Multiplet)
    !(sa == "level energies: interactive")   &&   error("Unsupported keystring = $sa")
    error("Not yet implemented !")

    return( nothing )
end

