code: public static String slicesToString(List<JsonSlice> slices) throws JsonFormatException,
  			IOException {
  		if (slices == null || slices.size() == 0) {
  			throw new JsonFormatException("slices is null or empty.");
  		}
  
  		StringWriter writer = new StringWriter();
  
  		int cnt = slices.size();
  		for (int i = 0; i < cnt; i++) {
  			JsonSlice slice = slices.get(i);
  			if (slice == null) {
  				throw new JsonFormatException("slice is null. i=" + i);
  			}
  			switch (slice.getState()) {
  				case START_ARRAY:
  					i = slicesToStringInArray(slices, i, writer);
  					break;
  				case START_HASH:
  					i = slicesToStringInHash(slices, i, writer);
  					break;
  				default:
  					throw new JsonFormatException("invalid state. i=" + i + " is "
  							+ slice.getState());
  			}
  		}
  
  		return writer.toString();
  	}
docs: Encodes the given list of {@link JsonSlice}s to valid JSON.
  
  @param slices List of {@link JsonSlice}s to encode
  @return Valid JSON-formatted string
  @throws JsonFormatException
  @throws IOException
  @author vvakame