public class ExprClient extends SimpleExpression<Player> {

    @Override
    public Class<? extends Player> getReturnType() {
            return Player.class;
    }

    @Override
    public boolean isSingle() {
            return true;
    }

    @Override
    public boolean init(Expression<?>[] e, int i, Kleenean kl, ParseResult pr) {
            if (!ScriptLoader.isCurrentEvent(TransactionEvent.class)) {
                    Skript.error(
                                    "Cannot use client in other events other than the transaction event",
                                    ErrorQuality.SEMANTIC_ERROR);
                    return false;
            }
            return true;
    }

    @Override
    public String toString(@Nullable Event e, boolean b) {
            return "Returns client";
    }

    @Override
    @Nullable
    protected Player[] get(Event e) {
            return new Player[] { ((TransactionEvent) e).getClient() };
    }

}