web/src/main/java/org/springframework/security/web/authentication/AnonymousAuthenticationFilter.java
@Override
	public void afterPropertiesSet() {
		Assert.hasLength(key, "key must have length");
		Assert.notNull(principal, "Anonymous authentication principal must be set");
		Assert.notNull(authorities, "Anonymous authorities must be set");
	}
@Override
	public void afterPropertiesSet() {
		Assert.hasLength(key, "key must have length");
		Assert.notNull(principal, "Anonymous authentication principal must be set");
		Assert.notNull(authorities, "Anonymous authorities must be set");
	}
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