Merge changes I8f5cd126,Ifdb59336,I6abae5ae,I5ec909df

* changes:
  Remove support for stuck threads
  Remove DisableOnDebug (new in 4.12) as it is not supported on Android
  Extra generic type information to aid certain javacs.
  Upgrade external/junit to 4.13.2

1 files changed, 37 insertions, 0 deletions

diff --git a/src/main/java/org/junit/internal/Checks.java b/src/main/java/org/junit/internal/Checks.java
new file mode 100644
index 0000000..9724947
--- /dev/null
+++ b/src/main/java/org/junit/internal/Checks.java
@@ -0,0 +1,37 @@
+package org.junit.internal;
+
+/** @since 4.13 */
+public final class Checks {
+
+    private Checks() {}
+
+    /**
+     * Checks that the given value is not {@code null}.
+     *
+     * @param value object reference to check
+     * @return the passed-in value, if not {@code null}
+     * @throws NullPointerException if {@code value} is {@code null}
+     */
+    public static <T> T notNull(T value) {
+        if (value == null) {
+            throw new NullPointerException();
+        }
+        return value;
+    }
+
+    /**
+     * Checks that the given value is not {@code null}, using the given message
+     * as the exception message if an exception is thrown.
+     *
+     * @param value object reference to check
+     * @param message message to use if {@code value} is {@code null}
+     * @return the passed-in value, if not {@code null}
+     * @throws NullPointerException if {@code value} is {@code null}
+     */
+    public static <T> T notNull(T value, String message) {
+        if (value == null) {
+            throw new NullPointerException(message);
+        }
+        return value;
+    }
+}