Fix example in Javadoc for Assert.notNull(object, messageSupplier)

Closes gh-25774

spring-core/src/main/java/org/springframework/util/Assert.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -80,8 +80,8 @@ public abstract class Assert {
 	 * <p>Call {@link #isTrue} if you wish to throw an {@code IllegalArgumentException}
 	 * on an assertion failure.
 	 * <pre class="code">
-	 * Assert.state(id == null,
-	 *     () -&gt; "ID for " + entity.getName() + " must not already be initialized");
+	 * Assert.state(entity.getId() == null,
+	 *     () -&gt; "ID for entity " + entity.getName() + " must not already be initialized");
 	 * </pre>
 	 * @param expression a boolean expression
 	 * @param messageSupplier a supplier for the exception message to use if the
@@ -202,7 +202,8 @@ public abstract class Assert {
 	/**
 	 * Assert that an object is not {@code null}.
 	 * <pre class="code">
-	 * Assert.notNull(clazz, () -&gt; "The class '" + clazz.getName() + "' must not be null");
+	 * Assert.notNull(entity.getId(),
+	 *     () -&gt; "ID for entity " + entity.getName() + " must not be null");
 	 * </pre>
 	 * @param object the object to check
 	 * @param messageSupplier a supplier for the exception message to use if the
@@ -244,7 +245,8 @@ public abstract class Assert {
 	 * Assert that the given String is not empty; that is,
 	 * it must not be {@code null} and not the empty String.
 	 * <pre class="code">
-	 * Assert.hasLength(name, () -&gt; "Name for account '" + account.getId() + "' must not be empty");
+	 * Assert.hasLength(account.getName(),
+	 *     () -&gt; "Name for account '" + account.getId() + "' must not be empty");
 	 * </pre>
 	 * @param text the String to check
 	 * @param messageSupplier a supplier for the exception message to use if the
@@ -289,7 +291,8 @@ public abstract class Assert {
 	 * Assert that the given String contains valid text content; that is, it must not
 	 * be {@code null} and must contain at least one non-whitespace character.
 	 * <pre class="code">
-	 * Assert.hasText(name, () -&gt; "Name for account '" + account.getId() + "' must not be empty");
+	 * Assert.hasText(account.getName(),
+	 *     () -&gt; "Name for account '" + account.getId() + "' must not be empty");
 	 * </pre>
 	 * @param text the String to check
 	 * @param messageSupplier a supplier for the exception message to use if the