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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def decipher_atom_key(atom_key, forcefield):
 """ Return element for deciphered atom key. This functions checks if the forcfield specified by user is supported and passes the atom key to the appropriate function for deciphering. Parameters atom_key : str The atom key which is to be deciphered. forcefield : str The forcefield to which the atom key belongs to. Returns ------- str A string that is the periodic table element equvalent of forcefield atom key. """

    load_funcs = {
        'DLF': dlf_notation,
        'DL_F': dlf_notation,
        'OPLS': opls_notation,
        'OPLSAA': opls_notation,
        'OPLS2005': opls_notation,
        'OPLS3': opls_notation,
    }
    if forcefield.upper() in load_funcs.keys():
        return load_funcs[forcefield.upper()](atom_key)
    else:
        raise _ForceFieldError(
            ("Unfortunetely, '{0}' forcefield is not supported by pyWINDOW."
             " For list of supported forcefields see User's Manual or "
             "MolecularSystem._decipher_atom_keys() function doc string."
             ).format(forcefield))