private void doClean(ThrowableSuppressor throwableSuppressor) {
        List<Cleanable> cleanablesCopy;

        synchronized (cleanables) {
            cleanablesCopy = new ArrayList<>(cleanables);
            cleanables.clear();
        }

        Collections.reverse(cleanablesCopy);

        for (Cleanable cleanable : cleanablesCopy) {
            throwableSuppressor.suppressAppend(cleanable::close);
        }
    }
Returns true if the Handle currently holds no database resources.
<br>
Note that this method will return <code>false</code> right after statement creation
as every statement registers its statement context with the handle. Once

@return True if the handle holds no database resources.
core/src/main/java/org/jdbi/v3/core/Handle.java