@GetMapping("/availableAgentCount")
	@PreAuthorize("permitAll")
	public Map<String, Integer> getAvailableAgentCount(User user,
													   @RequestParam String targetRegion,
													   @RequestParam(defaultValue = "") String targetSubregion) {
		return buildMap("availableAgentCount", agentService.getReadyAgentCount(user.getUserId(), targetRegion, targetSubregion));
	}
Get the number of available agents.

@param user         The login user
@param targetRegion The name of target region
@return availableAgentCount Available agent count
ngrinder-controller/src/main/java/org/ngrinder/agent/controller/AgentManagerApiController.java