diff --git a/src/main/java/me/mrletsplay/shareclientcore/connection/DummyConnection.java b/src/main/java/me/mrletsplay/shareclientcore/connection/DummyConnection.java
index 4bb0a87..63635cd 100644
--- a/src/main/java/me/mrletsplay/shareclientcore/connection/DummyConnection.java
+++ b/src/main/java/me/mrletsplay/shareclientcore/connection/DummyConnection.java
@@ -1,9 +1,31 @@
 package me.mrletsplay.shareclientcore.connection;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
 import me.mrletsplay.shareclientcore.connection.message.Message;
 
 public class DummyConnection implements RemoteConnection {
 
+	private int siteID;
+	private Consumer<Message> sendMessageHandler;
+	private List<MessageListener> listeners;
+
+	public DummyConnection(int siteID, Consumer<Message> sendMessageHandler) {
+		this.siteID = siteID;
+		this.sendMessageHandler = sendMessageHandler;
+		this.listeners = new ArrayList<>();
+	}
+
+	public DummyConnection(int siteID) {
+		this(siteID, null);
+	}
+
+	public void setSendMessageHandler(Consumer<Message> sendMessageHandler) {
+		this.sendMessageHandler = sendMessageHandler;
+	}
+
 	@Override
 	public void connect(String sessionID) throws ConnectionException {
 
@@ -16,22 +38,28 @@ public class DummyConnection implements RemoteConnection {
 
 	@Override
 	public int getSiteID() {
-		return 0;
+		return siteID;
 	}
 
 	@Override
 	public void send(Message message) {
+		if(sendMessageHandler != null) {
+			sendMessageHandler.accept(message);
+		}
+	}
 
+	public void receive(Message message) {
+		listeners.forEach(l -> l.onMessage(message));
 	}
 
 	@Override
 	public void addListener(MessageListener listener) {
-
+		listeners.add(listener);
 	}
 
 	@Override
 	public void removeListener(MessageListener listener) {
-
+		listeners.remove(listener);
 	}
 
 	@Override
diff --git a/src/test/java/me/mrletsplay/shareclientcore/DocumentTest.java b/src/test/java/me/mrletsplay/shareclientcore/DocumentTest.java
index 036d2b8..8835f66 100644
--- a/src/test/java/me/mrletsplay/shareclientcore/DocumentTest.java
+++ b/src/test/java/me/mrletsplay/shareclientcore/DocumentTest.java
@@ -12,7 +12,7 @@ public class DocumentTest {
 
 	@Test
 	public void testLocalInsert() {
-		SharedDocument doc = new SharedDocument(new DummyConnection(), "test");
+		SharedDocument doc = new SharedDocument(new DummyConnection(0), "test");
 		doc.localInsert(0, "Hello");
 		assertEquals("Hello", doc.getContentsAsString());
 		doc.localInsert(5, " World");
@@ -23,7 +23,7 @@ public class DocumentTest {
 
 	@Test
 	public void testLocalInsertInvalidIndexFails() {
-		SharedDocument doc = new SharedDocument(new DummyConnection(), "test");
+		SharedDocument doc = new SharedDocument(new DummyConnection(0), "test");
 		doc.localInsert(0, "Hello");
 		assertThrows(IllegalArgumentException.class, () -> doc.localInsert(-1, "Test"));
 		assertThrows(IllegalArgumentException.class, () -> doc.localInsert(6, "Test"));
@@ -31,7 +31,7 @@ public class DocumentTest {
 
 	@Test
 	public void testLocalDelete() {
-		SharedDocument doc = new SharedDocument(new DummyConnection(), "test");
+		SharedDocument doc = new SharedDocument(new DummyConnection(0), "test");
 		doc.localInsert(0, "Hello World!");
 		doc.localDelete(5, 6);
 		assertEquals("Hello!", doc.getContentsAsString());
@@ -39,7 +39,7 @@ public class DocumentTest {
 
 	@Test
 	public void testLocalDeleteInvalidIndexFails() {
-		SharedDocument doc = new SharedDocument(new DummyConnection(), "test");
+		SharedDocument doc = new SharedDocument(new DummyConnection(0), "test");
 		doc.localInsert(0, "Hello World!");
 		assertThrows(IllegalArgumentException.class, () -> doc.localDelete(-1, 10));
 		assertThrows(IllegalArgumentException.class, () -> doc.localDelete(12, 1));
diff --git a/src/test/java/me/mrletsplay/shareclientcore/SharingTest.java b/src/test/java/me/mrletsplay/shareclientcore/SharingTest.java
new file mode 100644
index 0000000..a2cd7e8
--- /dev/null
+++ b/src/test/java/me/mrletsplay/shareclientcore/SharingTest.java
@@ -0,0 +1,37 @@
+package me.mrletsplay.shareclientcore;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+import me.mrletsplay.shareclientcore.connection.DummyConnection;
+import me.mrletsplay.shareclientcore.document.SharedDocument;
+
+public class SharingTest {
+
+	@Test
+	public void testSharedDocument() {
+		DummyConnection a = new DummyConnection(0);
+		DummyConnection b = new DummyConnection(1);
+
+		a.setSendMessageHandler(m -> b.receive(m));
+		b.setSendMessageHandler(m -> a.receive(m));
+
+		SharedDocument sharedA = new SharedDocument(a, "doc");
+		SharedDocument sharedB = new SharedDocument(b, "doc");
+
+		a.addListener(sharedA);
+		b.addListener(sharedB);
+
+		sharedA.localInsert(0, "Hello World!");
+
+		assertEquals("Hello World!", sharedA.getContentsAsString());
+		assertEquals("Hello World!", sharedB.getContentsAsString());
+
+		sharedB.localInsert(0, "This is a test!");
+
+		assertEquals("This is a test!Hello World!", sharedA.getContentsAsString());
+		assertEquals("This is a test!Hello World!", sharedB.getContentsAsString());
+	}
+
+}