Polish MergedTestPropertySources

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

@@ -30,7 +30,7 @@ import org.springframework.util.Assert;
  */
 class MergedTestPropertySources {
 
-	private static final String[] EMPTY_STRING_ARRAY = new String[0];
+	private static final MergedTestPropertySources empty = new MergedTestPropertySources(new String[0], new String[0]);
 
 	private final String[] locations;
 
@@ -38,12 +38,13 @@ class MergedTestPropertySources {
 
 
 	/**
-	 * Create an <em>empty</em> {@code MergedTestPropertySources} instance.
+	 * Factory for an <em>empty</em> {@code MergedTestPropertySources} instance.
 	 */
-	MergedTestPropertySources() {
-		this(EMPTY_STRING_ARRAY, EMPTY_STRING_ARRAY);
+	static MergedTestPropertySources empty() {
+		return empty;
 	}
 
+
 	/**
 	 * Create a {@code MergedTestPropertySources} instance with the supplied
 	 * {@code locations} and {@code properties}.

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

@@ -92,7 +92,7 @@ public abstract class TestPropertySourceUtils {
 	static MergedTestPropertySources buildMergedTestPropertySources(Class<?> testClass) {
 		MergedAnnotations mergedAnnotations = MergedAnnotations.from(testClass, SearchStrategy.EXHAUSTIVE);
 		return (mergedAnnotations.isPresent(TestPropertySource.class) ? mergeTestPropertySources(mergedAnnotations) :
-				new MergedTestPropertySources());
+				MergedTestPropertySources.empty());
 	}
 
 	private static MergedTestPropertySources mergeTestPropertySources(MergedAnnotations mergedAnnotations) {