Move Assume to spring-boot-test-support

Fixes gh-10866

spring-boot-project/spring-boot-tools/spring-boot-test-support/src/main/java/org/springframework/boot/testsupport/Assume.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2012-2017 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.testsupport;
+
+import org.junit.AssumptionViolatedException;
+
+import org.springframework.util.ClassUtils;
+
+/**
+ * Provides utility methods that allow JUnit tests to {@link org.junit.Assume} certain
+ * conditions hold {@code true}. If the assumption fails, it means the test should be
+ * skipped.
+ *
+ * @author Stephane Nicoll
+ */
+public abstract class Assume {
+
+	public static void javaEight() {
+		if (ClassUtils.isPresent("java.security.cert.URICertStoreParameters", null)) {
+			throw new AssumptionViolatedException("Assumed Java 8 but got Java 9");
+		}
+	}
+
+}