code: @DELETE
  	@Produces(MediaType.APPLICATION_JSON)
  	@Path("/{chartId}")
  	@Description("Deletes a chart, given its id.")
  	public Response deleteChart(@Context HttpServletRequest req, @PathParam("chartId") BigInteger chartId) {
  		if (chartId == null || chartId.compareTo(BigInteger.ZERO) < 1) {
  			throw new WebApplicationException("chartId cannot be null and must be a positive non-zero number.", Status.BAD_REQUEST);
  		}
  
  		Chart chart = _chartService.getChartByPrimaryKey(chartId);
  		if (chart == null) {
  			throw new WebApplicationException("Chart with ID: " + chartId + " does not exist. Please use a valid chartId.", 
  					Response.Status.NOT_FOUND);
  		}
  		
  		PrincipalUser remoteUser = getRemoteUser(req);
  		_validateResourceAuthorization(remoteUser, chart.getOwner());
  		_chartService.deleteChart(chart);
  		return Response.status(Status.OK).build();
  	}
docs: Delete a chart, given its id.
  
  @param   req      The HttpServlet request object. Cannot be null.
  @param   chartId  The chart Id. Cannot be null and must be a positive non-zero number.
  
  @return  A Response object indicating whether the chart deletion was successful or not.
  
  @throws  WebApplicationException  An exception with 404 NOT_FOUND will be thrown if the chart does not exist.