public void set(int index, String value) throws IOException {
            Writer writer = null;
            try {
                writer = new OutputStreamWriter(newOutputStream(index), UTF_8);
                writer.write(value);
            } finally {
                closeQuietly(writer);
            }
        }
Sets the value at {@code index} to {@code value}.
app/src/main/java/com/duan/musicoco/cache/DiskLruCache.java