AuthenticationInfoPostProcessor for saml sso for aem6.5 with login

Hi ,

I would want inputs as how the AuthenticationInfoPostProcessor  will get invoked  for 

capturing saml response in java code using aem6.5.

If implement an component like below 

@Component(immediate = true, metatype = false)
@Service
public class SAMLResponsePostProcessor implements AuthenticationInfoPostProcessor {

1>Need inputs as How will this component be invoked by saml response after login.

I see entries in our code base like 

com.adobe.granite.auth.saml.SamlAuthenticationHandler-app1.xml  , we have like this 4 apps,I meant app1,app2,app3,app4.

I also see the as soon as the user logs in it creates a Node for the user details under /home with rep:user.

But don't see any entries in com.adobe.granite.auth.saml.SamlAuthenticationHandler-app1.xml   for user creation under 

/home with rep:user.

So how is that the above sample code will be hit when we saml login happens.

Please provide inputs

Thanks,

Srinivas