HBX-2747: Create Interface for ForeignKeyWrapper

  - Add new test case 'org.hibernate.tool.orm.jbt.api.ForeignKeyWrapperTest#testGetReferencedColumns()'
  - Add new default interface method 'org.hibernate.tool.orm.jbt.api.ForeignKeyWrapper#getReferencedColumns()'

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

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

@@ -1,6 +1,7 @@
 package org.hibernate.tool.orm.jbt.api;
 
 import java.util.Iterator;
+import java.util.List;
 
 import org.hibernate.mapping.Column;
 import org.hibernate.mapping.ForeignKey;
@@ -14,6 +15,8 @@ public interface ForeignKeyWrapper extends Wrapper {
 	default Iterator<Column> columnIterator() { return ((ForeignKey)getWrappedObject()).getColumns().iterator(); }
 
 	default boolean isReferenceToPrimaryKey() { return ((ForeignKey)getWrappedObject()).isReferenceToPrimaryKey(); }
+
+	default List<Column> getReferencedColumns() { return ((ForeignKey)getWrappedObject()).getReferencedColumns(); }
 
 
 }

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

@@ -1,12 +1,14 @@
 package org.hibernate.tool.orm.jbt.api;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.ArrayList;
 import java.util.Iterator;
+import java.util.List;
 
 import org.hibernate.mapping.Column;
 import org.hibernate.mapping.ForeignKey;
@@ -62,4 +64,17 @@ public void testIsReferenceToPrimaryKey() {
 		assertFalse(foreignKeyWrapper.isReferenceToPrimaryKey());
 	}
 
+	@Test
+	public void testGetReferencedColumns() {
+		List<Column> list = foreignKeyWrapper.getReferencedColumns();
+		assertTrue(list.isEmpty());		
+		Column column = new Column();
+		ArrayList<Column> columns = new ArrayList<Column>();
+		columns.add(column);
+		wrappedForeignKey.addReferencedColumns(columns);
+		list = foreignKeyWrapper.getReferencedColumns();
+		assertEquals(1, list.size());
+		assertSame(column, list.get(0));
+	}
+
 }