Polish "Fix JsonContentAssert type safety warnings"

- Format code
- Update an existing test to use the contains method that would
  previously have triggered a type safety warning

Closes gh-9675

spring-boot-test/src/main/java/org/springframework/boot/test/json/JsonContentAssert.java

@@ -951,8 +951,8 @@ public class JsonContentAssert extends AbstractAssert<JsonContentAssert, CharSeq
 	 * @throws AssertionError if the path is not valid or does not result in an array
 	 */
 	@SuppressWarnings("unchecked")
-	public <E> ListAssert<E> extractingJsonPathArrayValue(
-			CharSequence expression, Object... args) {
+	public <E> ListAssert<E> extractingJsonPathArrayValue(CharSequence expression,
+			Object... args) {
 		return Assertions.assertThat(
 				extractingJsonPathValue(expression, args, List.class, "an array"));
 	}
@@ -962,14 +962,14 @@ public class JsonContentAssert extends AbstractAssert<JsonContentAssert, CharSeq
 	 * @param expression the {@link JsonPath} expression
 	 * @param args arguments to parameterize the {@code JsonPath} expression with, using
 	 * @param <K> key type
-	 * @param <V> value type
-	 * formatting specifiers defined in {@link String#format(String, Object...)}
+	 * @param <V> value type formatting specifiers defined in
+	 * {@link String#format(String, Object...)}
 	 * @return a new assertion object whose object under test is the extracted item
 	 * @throws AssertionError if the path is not valid or does not result in a map
 	 */
 	@SuppressWarnings("unchecked")
-	public <K, V> MapAssert<K, V> extractingJsonPathMapValue(
-			CharSequence expression, Object... args) {
+	public <K, V> MapAssert<K, V> extractingJsonPathMapValue(CharSequence expression,
+			Object... args) {
 		return Assertions.assertThat(
 				extractingJsonPathValue(expression, args, Map.class, "a map"));
 	}

spring-boot-test/src/test/java/org/springframework/boot/test/json/JsonContentAssertTests.java

@@ -37,6 +37,7 @@ import org.springframework.test.util.JsonPathExpectationsHelper;
 import org.springframework.util.FileCopyUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.entry;
 
 /**
  * Tests for {@link JsonContentAssert}. Some tests here are based on Spring Framework
@@ -1252,7 +1253,7 @@ public class JsonContentAssertTests {
 	@Test
 	public void extractingJsonPathMapValue() throws Exception {
 		assertThat(forJson(TYPES)).extractingJsonPathMapValue("@.colorMap")
-				.containsEntry("red", "rojo");
+				.contains(entry("red", "rojo"));
 	}
 
 	@Test