private String extractSubregionFromFullRegion(String fullRegion) {
		if (isEmpty(fullRegion)) {
			return "";
		}

		String[] regionToken = fullRegion.split("\\.");
		return regionToken.length > 1 ? regionToken[1] : "";
	}
Get all approved agents for given user which are not used now.

@param  userId user id
@return AgentInfo set
ngrinder-controller/src/main/java/org/ngrinder/agent/service/AgentService.java