@Override
    public int read() throws IOException {
        ensureOpen();
        if (mPosition >= mLimit) {
            return -1;
        }

        return mString.charAt(mPosition++);
    }
@Test
    void testWrongLength() throws IOException {
        Assertions.assertThrows(IndexOutOfBoundsException.class, () -> {
            UnsafeStringReader reader = new UnsafeStringReader("abc");
            char[] chars = new char[1];
            reader.read(chars, 0, 2);
        });
    }