web/src/main/java/org/springframework/security/web/authentication/preauth/PreAuthenticatedGrantedAuthoritiesUserDetailsService.java
public final UserDetails loadUserDetails(PreAuthenticatedAuthenticationToken token)
			throws AuthenticationException {
		Assert.notNull(token.getDetails(), "token.getDetails() cannot be null");
		Assert.isInstanceOf(GrantedAuthoritiesContainer.class, token.getDetails());
		Collection<? extends GrantedAuthority> authorities = ((GrantedAuthoritiesContainer) token
				.getDetails()).getGrantedAuthorities();
		return createUserDetails(token, authorities);
	}
public final UserDetails loadUserDetails(PreAuthenticatedAuthenticationToken token)
			throws AuthenticationException {
		Assert.notNull(token.getDetails(), "token.getDetails() cannot be null");
		Assert.isInstanceOf(GrantedAuthoritiesContainer.class, token.getDetails());
		Collection<? extends GrantedAuthority> authorities = ((GrantedAuthoritiesContainer) token
				.getDetails()).getGrantedAuthorities();
		return createUserDetails(token, authorities);
	}
Get a UserDetails object based on the user name contained in the given token, and
the GrantedAuthorities as returned by the GrantedAuthoritiesContainer
implementation as returned by the token.getDetails() method.