@Override
     public List<org.openstack4j.model.compute.Image> extractOpenstackImagesFromServers(final List<Server> servers) {
         Objects.requireNonNull(osClient, ERR_MSG_NULL_OS_CLIENT);
-        return servers.stream().map(Server::getImage)
+        return servers.stream().filter(s -> s.getImage() != null).map(Server::getImage)
                 .filter(distinctByProperty(org.openstack4j.model.compute.Image::getId)).collect(Collectors.toList());
     }
 
 
 import org.openstack4j.model.network.Subnet;
 import org.openstack4j.openstack.heat.domain.HeatResource;
 import org.openstack4j.openstack.heat.domain.HeatResource.Resources;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.core.env.Environment;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.core.type.TypeReference;
     private static final String TENANT_ID = "7320ec4a5b9d4589ba7c4412ccfd290f";
     private static final ObjectMapper MAPPER = new ObjectMapper();
 
+    private static Logger logger = LoggerFactory.getLogger(HeatBridgeImplTest.class);
+
     @Mock
     private OpenstackClient osClient;
 
     @Mock
     private Server server;
 
+    @Mock
+    private Server server2;
+
+    @Mock
+    private Image image;
+
     @Mock
     private AAIDSLQueryClient dSLQueryClient;
 
         verify(osClient, times(5)).getNetworkById(anyString());
     }
 
+
+    @Test
+    public void testExtractOpenstackImagesFromServers() throws HeatBridgeException {
+        // Arrange
+        List<Server> serverList = new ArrayList<>();
+        serverList.add(server);
+        serverList.add(server2);
+        when(server.getImage()).thenReturn(null);
+        when(server.getImage()).thenReturn(image);
+        when(image.getId()).thenReturn("imageId");
+        // Act
+
+        List<Image> images = heatbridge.extractOpenstackImagesFromServers(serverList);
+
+
+        // Assert
+        assertEquals(1, images.size());
+    }
+
     private List<? extends Resource> extractTestStackResources() {
         List<HeatResource> stackResources = null;
         try {
         return stackResources;
     }
 
+
     private String readTestResourceFile(String filePath) {
         String content = null;
         String pathname = Objects.requireNonNull(getClass().getClassLoader().getResource(filePath)).getFile();