diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..8095ada
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,27 @@
+# Compiled class files
+*.class
+
+# Log files
+*.log
+
+# Package files
+*.jar
+!zapsdtest/zjunit/*.jar
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# IDE specific files
+.idea/
+*.iml
+.vscode/
+.project
+.classpath
+.settings/
+
+# OS generated files
+.DS_Store
+Thumbs.db
diff --git a/apsd/classes/containers/sequences/abstractbases/VectorBase.java b/apsd/classes/containers/sequences/abstractbases/VectorBase.java
index 21700a9..2a8d4e8 100644
--- a/apsd/classes/containers/sequences/abstractbases/VectorBase.java
+++ b/apsd/classes/containers/sequences/abstractbases/VectorBase.java
@@ -102,12 +102,10 @@ public MutableBackwardIterator<Data> BIterator() {
   /* Override specific member functions from Sequence                         */
   /* ************************************************************************ */
 
-  @SuppressWarnings("unchecked")
   @Override
   public MutableSequence<Data> SubSequence(Natural start, Natural end) {
-      Data[] arrCopy;
-
-      return (MutableSequence) arrCopy;
+      // TODO: implement SubSequence
+      throw new UnsupportedOperationException("SubSequence not yet implemented");
   }
 
   /* ************************************************************************ */