Documentation has only an XML namespace introduction to eraseCredentialsAfterAuthentication

Expected Behavior

In Spring Security 5.6.2, the process of configuring AuthenticationManagerBuilder.eraseCredentials(false); is relatively intuitive, but it does not correspond to https://docs.spring.io/spring-security/reference/servlet/configuration/java.html instruction of.

@Order(1)
@Configuration
public static class ApiWebSecurityConfigurerAdapter extends WebSecurityConfigurerAdapter {
           @Override
           protected void configure(HttpSecurity http) throws Exception {
                http.authorizeHttpRequests((authz) -> authz.anyRequest().authenticated())
                      .httpBasic(withDefaults());
            }

          @Override
          protected void configure(AuthenticationManagerBuilder auth) throws Exception {
            auth.eraseCredentials(false);
          }
}

• This problem extends to the documentation of Spring Security 5.7.0-M3, and the lack of documentation brings more trouble to users, refer to https://docs.spring.io/spring-security/reference/5.7.0-M3/servlet/appendix/namespace/authentication-manager.html#nsa-authentication-manager-attributes .
• 

Current Behavior

• I think a simple example should be added at https://docs.spring.io/spring-security/reference/5.7.0-M3/servlet/configuration/java.html to modify eraseCredentialsAfterAuthentication .

Context

No.

Start with the servlet Java configuration documentation at the referenced configuration/java.html page and compare it with the namespace authentication-manager documentation. Add a simple Java configuration example showing how to modify eraseCredentialsAfterAuthentication, then verify that the setting is explained consistently for the referenced Spring Security versions.