Add test for ContainerConfig deserialization without nullables

src/test/java/com/spotify/docker/client/messages/ContainerConfigTest.java

@@ -21,6 +21,9 @@
 package com.spotify.docker.client.messages;
 
 import static com.spotify.docker.FixtureUtil.fixture;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.spotify.docker.client.ObjectMapperProvider;
@@ -46,4 +49,18 @@ public void test1_29() throws Exception {
     objectMapper.readValue(fixture("fixtures/1.29/containerConfig.json"), ContainerConfig.class);
   }
 
+  @Test
+  public void test1_29_WithoutNullables() throws Exception {
+    final ContainerConfig config = objectMapper.readValue(
+        fixture("fixtures/1.29/containerConfigWithoutNullables.json"), ContainerConfig.class);
+    assertThat(config.portSpecs(), is(nullValue()));
+    assertThat(config.exposedPorts(), is(nullValue()));
+    assertThat(config.env(), is(nullValue()));
+    assertThat(config.cmd(), is(nullValue()));
+    assertThat(config.entrypoint(), is(nullValue()));
+    assertThat(config.onBuild(), is(nullValue()));
+    assertThat(config.labels(), is(nullValue()));
+    assertThat(config.healthcheck(), is(nullValue()));
+  }
+
 }

src/test/resources/fixtures/1.29/containerConfigWithoutNullables.json

@@ -0,0 +1,24 @@
+{
+  "Hostname": "string",
+  "Domainname": "string",
+  "User": "string",
+  "AttachStdin": false,
+  "AttachStdout": true,
+  "AttachStderr": true,
+  "Tty": false,
+  "OpenStdin": false,
+  "StdinOnce": false,
+  "ArgsEscaped": true,
+  "Image": "string",
+  "Volumes": {
+    "additionalProperties": {}
+  },
+  "WorkingDir": "string",
+  "NetworkDisabled": true,
+  "MacAddress": "string",
+  "StopSignal": "SIGTERM",
+  "StopTimeout": 10,
+  "Shell": [
+    "string"
+  ]
+}