Remove explicit type arguments

See gh-10494

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/ImportsContextCustomizer.java

@@ -245,7 +245,7 @@ class ImportsContextCustomizer implements ContextCustomizer {
 			Set<Class<?>> seen = new HashSet<>();
 			collectClassAnnotations(testClass, annotations, seen);
 			Set<Object> determinedImports = determineImports(annotations, testClass);
-			this.key = Collections.<Object>unmodifiableSet(
+			this.key = Collections.unmodifiableSet(
 					determinedImports != null ? determinedImports : annotations);
 		}
 
@@ -321,7 +321,7 @@ class ImportsContextCustomizer implements ContextCustomizer {
 				return null;
 			}
 			// The source itself is the import
-			return Collections.<Object>singleton(source.getName());
+			return Collections.singleton(source.getName());
 		}
 
 		@SuppressWarnings("unchecked")

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/DefinitionsParser.java

@@ -46,7 +46,7 @@ class DefinitionsParser {
 	private final Map<Definition, Field> definitionFields;
 
 	DefinitionsParser() {
-		this(Collections.<Definition>emptySet());
+		this(Collections.emptySet());
 	}
 
 	DefinitionsParser(Collection<? extends Definition> existing) {

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/ImportsContextCustomizerTests.java

@@ -162,7 +162,7 @@ public class ImportsContextCustomizerTests {
 
 		@Override
 		public Set<Object> determineImports(AnnotationMetadata metadata) {
-			return Collections.<Object>singleton(TestConfig.class.getName());
+			return Collections.singleton(TestConfig.class.getName());
 		}
 
 	}