unused imports

config/src/main/java/org/springframework/security/config/annotation/SecurityConfigurerAdapter.java

@@ -16,7 +16,6 @@
 package org.springframework.security.config.annotation;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 import org.springframework.core.GenericTypeResolver;

config/src/main/java/org/springframework/security/config/annotation/web/builders/HttpSecurity.java

@@ -78,7 +78,6 @@ import org.springframework.web.servlet.handler.HandlerMappingIntrospector;
 import javax.servlet.Filter;
 import javax.servlet.http.HttpServletRequest;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 

config/src/main/java/org/springframework/security/config/annotation/web/configuration/WebSecurityConfiguration.java

@@ -15,7 +15,6 @@
  */
 package org.springframework.security.config.annotation.web.configuration;
 
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import javax.servlet.Filter;

core/src/main/java/org/springframework/security/jackson2/UnmodifiableListDeserializer.java

@@ -27,7 +27,6 @@ import com.fasterxml.jackson.databind.node.ArrayNode;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.List;
 
 /**

core/src/main/java/org/springframework/security/jackson2/UnmodifiableSetDeserializer.java

@@ -27,7 +27,6 @@ import com.fasterxml.jackson.databind.node.ArrayNode;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.Set;
 
 /**