Implemented the error handling in case of commucation failures

spring-boot-samples/spring-boot-sample-websocket/src/test/java/org/springframework/boot/samples/websocket/snake/SnakeTimerTests.java

@@ -0,0 +1,24 @@
+package org.springframework.boot.samples.websocket.snake;
+
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+
+public class SnakeTimerTests {
+
+    @Test
+    public void removeDysfunctionalSnakes() throws Exception {
+        Snake snake = mock(Snake.class);
+        doThrow(new IOException()).when(snake).sendMessage(anyString());
+        SnakeTimer.addSnake(snake);
+
+        SnakeTimer.broadcast("");
+        assertThat(SnakeTimer.getSnakes().size(), is(0));
+    }
+}