public static void checkSingleMana(String m) {
        if (m.length() != 1) throw new RuntimeException(
                "Mana_Part : checkMana() error, argument mana is not of length 1, mana - " + m);

        if (!(m.equals("G") || m.equals("U") || m.equals("W") || m.equals("B") || m.equals("R") || m.equals("1") || m.equals("S") || m.startsWith("P")))
            throw new RuntimeException(
                    "Mana_Part : checkMana() error, argument mana is invalid mana, mana - " + m);
    }