This is a module of a security method that's provided by Spring Security. We can provide a role in a particular function so that role-based users can access the function. 

The following annotation is used to enable this feature:

 @EnableGlobalMethodSecurity(securedEnabled = true)

Here's an example of how to enable method security in the SpringSecurityApplication.kt class, which is the main application class of our demo project:

@SpringBootApplication
@EnableGlobalMethodSecurity(securedEnabled = true)
class SpringSecurityApplication{

    fun main(args: Array<String>) {
        runApplication<SpringSecurityApplication>(*args)
    }
}

Now you can create the method resources, such as the following code:

@Secured
class CustomService{
    @Secured
    fun secure(): String{
        return "The is Secured..."
    }
}

Here, we created a secured class named CustomService using the @Secured annotation, and then created a secured function that will return a spring. The @Secured annotation is used to specify a list of roles on a function.