public String(String original) {
        int size = original.count;
        char[] originalValue = original.value;
        char[] v;
        if (originalValue.length > size) {
            // The array representing the String is bigger than the new
            // String itself.  Perhaps this constructor is being called
            // in order to trim the baggage, so make a copy of the array.
            int off = original.offset;
            v = Arrays.copyOfRange(originalValue, off, off+size);
        } else {
            // The array representing the String is the same
            // size as the String, so no point in making a copy.
            v = originalValue;
        }
        this.offset = 0;
        this.count = size;
        this.value = v;
    }

    // imagine a multi-megabyte string here
    String s = "0123456789012345678901234567890123456789";
    String s2 = s.substring(0, 1);
     s = null; 

String s2 = new String(s.substring(0, 1));