Rewrite groovy test as junit

netcdf4/build.gradle

@@ -31,7 +31,6 @@ dependencies {
 
 sourceSets {
   unloadedTest {
-    groovy.srcDir file('src/unloadedTest/groovy')
     resources.srcDir file('src/unloadedTest/resources')
     compileClasspath += sourceSets.main.output + configurations.testCompileClasspath
     runtimeClasspath += output + sourceSets.main.output + configurations.testRuntimeClasspath

netcdf4/src/unloadedTest/java/ucar/nc2/jni/netcdf/TestUnloadedNc4Iosp.java

@@ -0,0 +1,20 @@
+package ucar.nc2.jni.netcdf;
+
+import java.io.IOException;
+import org.junit.Test;
+import ucar.nc2.Attribute;
+
+public class TestUnloadedNc4Iosp {
+
+  @Test
+  public void shouldFlushInDefineModeWithoutCLib() throws IOException {
+    Nc4Iosp nc4Iosp = new Nc4Iosp();
+    nc4Iosp.flush();
+  }
+
+  @Test
+  public void shouldUpdateAttributeInDefineModeWithoutCLib() throws IOException {
+    Nc4Iosp nc4Iosp = new Nc4Iosp();
+    nc4Iosp.updateAttribute(null, new Attribute("foo", "bar"));
+  }
+}