code

/** * An extension of ThreadLocal that obtains its initial value from * the specified {@code Supplier}. */static final class SuppliedThreadLocal<T> extends ThreadLocal<T> {    private final Supplier<? extends T> supplier;    SuppliedThreadLocal(Supplier<? extends T> supplier) {        this.supplier = Objects.requireNonNull(supplier);    }    @Override    protected T initialValue() {        return supplier.get();    }}