Consistently declare Object::equals argument as @Nullable

spring-test/src/main/java/org/springframework/test/context/support/DynamicPropertiesContextCustomizer.java

@@ -26,6 +26,7 @@ import java.util.function.Supplier;
 
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.core.env.MutablePropertySources;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextCustomizer;
 import org.springframework.test.context.DynamicPropertyRegistry;
 import org.springframework.test.context.DynamicPropertySource;
@@ -96,7 +97,7 @@ class DynamicPropertiesContextCustomizer implements ContextCustomizer {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		if (this == obj) {
 			return true;
 		}

spring-test/src/main/java/org/springframework/test/web/reactive/server/XpathAssertions.java

@@ -190,7 +190,7 @@ public class XpathAssertions {
 
 
 	@Override
-	public boolean equals(Object obj) {
+	public boolean equals(@Nullable Object obj) {
 		throw new AssertionError("Object#equals is disabled " +
 				"to avoid being used in error instead of XPathAssertions#isEqualTo(String).");
 	}

spring-test/src/test/java/org/springframework/test/web/Person.java

@@ -19,6 +19,7 @@ package org.springframework.test.web;
 import jakarta.validation.constraints.NotNull;
 import jakarta.xml.bind.annotation.XmlRootElement;
 
+import org.springframework.lang.Nullable;
 import org.springframework.util.ObjectUtils;
 
 @XmlRootElement
@@ -66,7 +67,7 @@ public class Person {
 	}
 
 	@Override
-	public boolean equals(Object other) {
+	public boolean equals(@Nullable Object other) {
 		if (this == other) {
 			return true;
 		}

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/Person.java

@@ -20,6 +20,8 @@ import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import jakarta.xml.bind.annotation.XmlRootElement;
 
+import org.springframework.lang.Nullable;
+
 @XmlRootElement
 class Person {
 
@@ -44,7 +46,7 @@ class Person {
 	}
 
 	@Override
-	public boolean equals(Object other) {
+	public boolean equals(@Nullable Object other) {
 		if (this == other) {
 			return true;
 		}