HBX-2754: Create Interface for JoinWrapper

  - Create new initial test class 'org.hibernate.tool.orm.jbt.api.JoinWrapperTest'
  - Create new initial interface class 'org.hibernate.tool.orm.jbt.api.JoinWrapper'
  - Create new factory class 'org.hibernate.tool.orm.jbt.internal.factory.JoinWrapperFactory'

Signed-off-by: Koen Aers <koen.aers@gmail.com>

jbt/src/main/java/org/hibernate/tool/orm/jbt/api/JoinWrapper.java

@@ -0,0 +1,7 @@
+package org.hibernate.tool.orm.jbt.api;
+
+import org.hibernate.tool.orm.jbt.wrp.Wrapper;
+
+public interface JoinWrapper extends Wrapper {
+
+}

jbt/src/main/java/org/hibernate/tool/orm/jbt/internal/factory/JoinWrapperFactory.java

@@ -0,0 +1,14 @@
+package org.hibernate.tool.orm.jbt.internal.factory;
+
+import org.hibernate.mapping.Join;
+import org.hibernate.tool.orm.jbt.api.JoinWrapper;
+
+public class JoinWrapperFactory {
+
+	public static JoinWrapper createJoinWrapper(Join wrappedJoin) {
+		return new JoinWrapper() {
+			@Override public Join getWrappedObject() { return wrappedJoin; }
+		};
+	}
+
+}

jbt/src/test/java/org/hibernate/tool/orm/jbt/api/JoinWrapperTest.java

@@ -0,0 +1,27 @@
+package org.hibernate.tool.orm.jbt.api;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import org.hibernate.mapping.Join;
+import org.hibernate.tool.orm.jbt.internal.factory.JoinWrapperFactory;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class JoinWrapperTest {
+
+	private JoinWrapper joinWrapper = null;
+	private Join wrappedJoin = null;
+
+	@BeforeEach
+	public void beforeEach() {
+		wrappedJoin = new Join();
+		joinWrapper = JoinWrapperFactory.createJoinWrapper(wrappedJoin);
+	}
+
+	@Test
+	public void testConstruction() {
+		assertNotNull(wrappedJoin);
+		assertNotNull(joinWrapper);
+	}
+
+}