Support for functional routing by API version

See gh-35113

spring-web/src/main/java/org/springframework/web/accept/DefaultApiVersionStrategy.java

@@ -91,6 +91,16 @@ public class DefaultApiVersionStrategy implements ApiVersionStrategy {
 		return this.defaultVersion;
 	}
 
+	/**
+	 * Whether the strategy is configured to detect supported versions.
+	 * If this is set to {@code false} then {@link #addMappedVersion} is ignored
+	 * and the list of supported versions can be built explicitly through calls
+	 * to {@link #addSupportedVersion}.
+	 */
+	public boolean detectSupportedVersions() {
+		return this.detectSupportedVersions;
+	}
+
 	/**
 	 * Add to the list of supported versions to check against in
 	 * {@link ApiVersionStrategy#validateVersion} before raising