For #1526: support to github pull request draft

src/main/java/com/jcabi/github/Pull.java

@@ -319,6 +319,14 @@ public Issue issue() {
         public int commentsCount() throws IOException {
             return this.jsn.number("comments");
         }
+        /**
+         * Is it a draft pull request?
+         * @return TRUE if it's a draft pull request
+         * @throws IOException If there is any I/O problem
+         */
+        public boolean isDraft() throws IOException {
+            return this.jsn.json().getBoolean("draft");
+        }
         @Override
         public Repo repo() {
             return this.pull.repo();

src/test/java/com/jcabi/github/PullTest.java

@@ -34,6 +34,7 @@
 import javax.json.Json;
 import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
+import org.hamcrest.core.IsEqual;
 import org.junit.Test;
 import org.mockito.Mockito;
 
@@ -127,4 +128,29 @@ public void getsAuthor() throws IOException {
             Matchers.equalTo(login)
         );
     }
+
+    /**
+     * Pull.Smart can get the pull request draft state.
+     * @throws IOException If some problem inside
+     */
+    @Test
+    public void getDraftState() throws IOException {
+        final Repo repo = Mockito.mock(Repo.class);
+        Mockito.when(repo.github()).thenReturn(new MkGithub());
+        final Pull pull = Mockito.mock(Pull.class);
+        Mockito.when(pull.json()).thenReturn(
+            Json.createObjectBuilder()
+                .add(
+                    "draft",
+                    true
+                )
+                .build()
+        );
+        Mockito.when(pull.repo()).thenReturn(repo);
+        MatcherAssert.assertThat(
+            "Could not retrieve correct draft status",
+            new Pull.Smart(pull).isDraft(),
+            new IsEqual<>(true)
+        );
+    }
 }