core/src/main/java/org/springframework/security/authentication/jaas/SecurityContextLoginModule.java
@SuppressWarnings("unchecked")
	public void initialize(Subject subject, CallbackHandler callbackHandler,
			Map sharedState, Map options) {
		this.subject = subject;

		if (options != null) {
			ignoreMissingAuthentication = "true".equals(options
					.get("ignoreMissingAuthentication"));
		}
	}
@SuppressWarnings("unchecked")
	public void initialize(Subject subject, CallbackHandler callbackHandler,
			Map sharedState, Map options) {
		this.subject = subject;

		if (options != null) {
			ignoreMissingAuthentication = "true".equals(options
					.get("ignoreMissingAuthentication"));
		}
	}
Initialize this <code>LoginModule</code>. Ignores the callback handler, since the
code establishing the <code>LoginContext</code> likely won't provide one that
understands Spring Security. Also ignores the <code>sharedState</code> and
<code>options</code> parameters, since none are recognized.

@param subject the <code>Subject</code> to be authenticated.
@param callbackHandler is ignored
@param sharedState is ignored
@param options are ignored