public String putAlias(String alias, String key)
    {
        if (aliases.containsKey(key))
        {
            throw new IllegalArgumentException("The key \"" + key + "\" to alias is already present in the kernel parameters.");
        }
        return aliases.put(key, alias);
    }
public String putAlias ( String alias , String key ) { if ( aliases . containsKey ( key ) ) { throw new IllegalArgumentException ( "The key \"" + key + "\" to alias is already present in the kernel parameters." ) ; } return aliases . put ( key , alias ) ; }
@param key   the key to alias.
@param alias the alias to give to the key.
@return the previous alias corresponding the key