diff --git a/waltz-common/src/test/java/org/finos/waltz/common/BatchProcessingCollectorTest.java b/waltz-common/src/test/java/org/finos/waltz/common/BatchProcessingCollectorTest.java
new file mode 100644
index 0000000000..0996c88228
--- /dev/null
+++ b/waltz-common/src/test/java/org/finos/waltz/common/BatchProcessingCollectorTest.java
@@ -0,0 +1,31 @@
+package org.finos.waltz.common;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class BatchProcessingCollectorTest {
+
+    @Test
+    public void batchingWorksAndReportsNumberOfItemsProcessed() {
+        ArrayList<String> data = ListUtilities.newArrayList("A", "B", "C", "D");
+        List<String> batched = new ArrayList<>();
+
+        BatchProcessingCollector<String> batchProcessor = new BatchProcessingCollector<>(
+                3,
+                xs -> {
+                    batched.add(StringUtilities.join(xs, "!"));
+                });
+
+        Integer rc = data
+                .stream()
+                .collect(batchProcessor);
+
+        assertEquals(4, rc, "Should have processed all input items");
+        assertEquals(ListUtilities.asList("A!B!C", "D"), batched);
+    }
+}
diff --git a/waltz-common/src/test/java/org/finos/waltz/common/Columns_toOffsetTest.java b/waltz-common/src/test/java/org/finos/waltz/common/Columns_toOffsetTest.java
new file mode 100644
index 0000000000..9df97a5b89
--- /dev/null
+++ b/waltz-common/src/test/java/org/finos/waltz/common/Columns_toOffsetTest.java
@@ -0,0 +1,15 @@
+package org.finos.waltz.common;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Columns_toOffsetTest {
+
+    @Test
+    public void toOffset() {
+        assertEquals(Columns.A, Columns.toOffset("A"));
+        assertEquals(Columns.BA, Columns.toOffset("BA"));
+        assertEquals(53, Columns.toOffset("BB"));
+    }
+}
diff --git a/waltz-common/src/test/java/org/finos/waltz/common/ListUtilities_getOrDefaultTest.java b/waltz-common/src/test/java/org/finos/waltz/common/ListUtilities_getOrDefaultTest.java
new file mode 100644
index 0000000000..a44c877994
--- /dev/null
+++ b/waltz-common/src/test/java/org/finos/waltz/common/ListUtilities_getOrDefaultTest.java
@@ -0,0 +1,22 @@
+package org.finos.waltz.common;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.finos.waltz.common.ListUtilities.getOrDefault;
+import static org.finos.waltz.common.TestUtilities.assertLength;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ListUtilities_getOrDefaultTest {
+
+    @Test
+    public void getOrDefaultTests(){
+        List<String> arr = ListUtilities.newArrayList("a", "b");
+        assertEquals("a", getOrDefault(arr, 0, "z"));
+        assertEquals("b", getOrDefault(arr, 1, "z"));
+        assertEquals("z", getOrDefault(arr, 100, "z"));
+        assertEquals("z", getOrDefault(arr, -1, "z"));
+
+    }
+}
diff --git a/waltz-common/src/test/java/org/finos/waltz/common/StreamUtilities_siphonTest.java b/waltz-common/src/test/java/org/finos/waltz/common/StreamUtilities_siphonTest.java
new file mode 100644
index 0000000000..87669459e8
--- /dev/null
+++ b/waltz-common/src/test/java/org/finos/waltz/common/StreamUtilities_siphonTest.java
@@ -0,0 +1,32 @@
+package org.finos.waltz.common;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.finos.waltz.common.StreamUtilities.mkSiphon;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class StreamUtilities_siphonTest {
+
+    @Test
+    public void siphon(){
+        StreamUtilities.Siphon<String> siphon = mkSiphon(x -> x.startsWith("h"));
+
+        List<String> result = Stream
+                .of("hello", "world", "happy", "earth", "hip", "hip", "hooray")
+                .filter(siphon)
+                .collect(Collectors.toList());
+
+        assertEquals(ListUtilities.asList("world", "earth"), result);
+        assertTrue(siphon.hasResults());
+        assertEquals(ListUtilities.asList("hello", "happy", "hip", "hip", "hooray"), siphon.getResults());
+
+    }
+}