diff --git a/hw4/diagram.png b/hw4/diagram.png
new file mode 100644
index 0000000..b8c9376
Binary files /dev/null and b/hw4/diagram.png differ
diff --git a/hw4/diagram.uml b/hw4/diagram.uml
new file mode 100644
index 0000000..9332872
--- /dev/null
+++ b/hw4/diagram.uml
@@ -0,0 +1,80 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Diagram>
+  <ID>JAVA</ID>
+  <OriginalElement />
+  <nodes>
+    <node x="-90.5" y="176.0">ShapeIcon</node>
+    <node x="-76.0" y="-4.0">CompositeShape</node>
+    <node x="-50.0" y="296.0">ShapeDisplayer</node>
+    <node x="12.5" y="116.0">CarShape</node>
+    <node x="208.0" y="116.0">SnowmanShape</node>
+    <node x="101.5" y="176.0">HouseShape</node>
+  </nodes>
+  <notes />
+  <edges>
+    <edge source="CarShape" target="CompositeShape" relationship="REALIZATION">
+      <point x="62.5" y="0.0" />
+      <point x="173.0" y="130.0" />
+      <point x="173.0" y="10.0" />
+      <point x="91.0" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="CompositeShape" relationship="TO_ONE">
+      <point x="-2.0" y="-14.0" />
+      <point x="33.0" y="221.5" />
+      <point x="-108.0" y="221.5" />
+      <point x="-108.0" y="10.0" />
+      <point x="-91.0" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="SnowmanShape" relationship="CREATE">
+      <point x="85.0" y="0.0" />
+      <point x="295.0" y="310.0" />
+      <point x="0.0" y="14.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="HouseShape" relationship="CREATE">
+      <point x="77.5" y="-14.0" />
+      <point x="-62.5" y="14.0" />
+    </edge>
+    <edge source="ShapeIcon" target="CompositeShape" relationship="TO_ONE">
+      <point x="98.125" y="-0.08333333333334281" />
+      <point x="-298.1666666666667" y="189.91666666666666" />
+      <point x="-298.1666666666667" y="212.33333333333337" />
+      <point x="-108.0" y="212.33333333333337" />
+      <point x="-108.0" y="10.0" />
+      <point x="-91.0" y="0.0" />
+    </edge>
+    <edge source="SnowmanShape" target="CompositeShape" relationship="REALIZATION">
+      <point x="-87.0" y="0.0" />
+      <point x="173.0" y="130.0" />
+      <point x="173.0" y="10.0" />
+      <point x="91.0" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="ShapeIcon" relationship="TO_ONE">
+      <point x="-60.0" y="-14.0" />
+      <point x="0.0" y="14.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="CarShape" relationship="CREATE">
+      <point x="-85.0" y="0.0" />
+      <point x="-123.0" y="310.0" />
+      <point x="-123.0" y="130.0" />
+      <point x="-62.5" y="0.0" />
+    </edge>
+    <edge source="ShapeDisplayer" target="ShapeIcon" relationship="CREATE">
+      <point x="-45.0" y="-14.0" />
+      <point x="15.0" y="14.0" />
+    </edge>
+    <edge source="HouseShape" target="CompositeShape" relationship="REALIZATION">
+      <point x="73.5" y="0.0" />
+      <point x="399.5" y="190.0" />
+      <point x="399.5" y="60.5" />
+      <point x="173.0" y="60.5" />
+      <point x="173.0" y="10.0" />
+      <point x="91.0" y="0.0" />
+    </edge>
+  </edges>
+  <settings layout="Hierarchic Compact" zoom="1.2" showDependencies="true" x="233.54166666666663" y="134.91666666666666" />
+  <SelectedNodes />
+  <Categories />
+  <SCOPE>All</SCOPE>
+  <VISIBILITY>private</VISIBILITY>
+</Diagram>
+