code: @Private
    static StringBuilder read(Readable from) throws IOException {
      StringBuilder builder = new StringBuilder();
      CharBuffer buf = CharBuffer.allocate(2048);
      for (; ; ) {
        int r = from.read(buf);
        if (r == -1) break;
        buf.flip();
        builder.append(buf, 0, r);
      }
      return builder;
    }
docs: Copies all content from {@code from} to {@code to}.