Improve support for EventChange objects (#362)

* Set visible the event name on web hooks
* Add state to possible event changes
* Add support for arbitrary elements inside EventChange JSON object

src/main/java/org/gitlab4j/api/webhook/EventChanges.java

-package org.gitlab4j.api.webhook;
-
-import java.util.Date;
-import java.util.List;
-
-import org.gitlab4j.api.models.Assignee;
-import org.gitlab4j.api.utils.JacksonJson;
-
-public class EventChanges {
-
-    private ChangeContainer<Date> updatedAt;
-    private ChangeContainer<Integer> updatedById;
-    private ChangeContainer<Date> dueDate;
-    private ChangeContainer<Integer> milestoneId;
-    private ChangeContainer<List<EventLabel>> labels;
-    private ChangeContainer<List<Assignee>> assignees;
-    private ChangeContainer<Integer> totalTimeSpent;
-    private ChangeContainer<Boolean> confidential;
-
-    public ChangeContainer<Date> getUpdatedAt() {
-        return updatedAt;
-    }
-
-    public void setUpdatedAt(ChangeContainer<Date> updatedAt) {
-        this.updatedAt = updatedAt;
-    }
-
-    public ChangeContainer<Integer> getUpdatedById() {
-        return updatedById;
-    }
-
-    public void setUpdatedById(ChangeContainer<Integer> updatedById) {
-        this.updatedById = updatedById;
-    }
-
-    public ChangeContainer<Date> getDueDate() {
-        return dueDate;
-    }
-
-    public void setDueDate(ChangeContainer<Date> dueDate) {
-        this.dueDate = dueDate;
-    }
-
-    public ChangeContainer<Integer> getMilestoneId() {
-        return milestoneId;
-    }
-
-    public void setMilestoneId(ChangeContainer<Integer> milestoneId) {
-        this.milestoneId = milestoneId;
-    }
-
-    public ChangeContainer<List<EventLabel>> getLabels() {
-        return labels;
-    }
-
-    public void setLabels(ChangeContainer<List<EventLabel>> labels) {
-        this.labels = labels;
-    }
-
-    public ChangeContainer<List<Assignee>> getAssignees() {
-        return assignees;
-    }
-
-    public void setAssignees(ChangeContainer<List<Assignee>> assignees) {
-        this.assignees = assignees;
-    }
-
-    public ChangeContainer<Integer> getTotalTimeSpent() {
-        return totalTimeSpent;
-    }
-
-    public void setTotalTimeSpent(ChangeContainer<Integer> totalTimeSpent) {
-        this.totalTimeSpent = totalTimeSpent;
-    }
-
-    public ChangeContainer<Boolean> getConfidential() {
-        return confidential;
-    }
-
-    public void setConfidential(ChangeContainer<Boolean> confidential) {
-        this.confidential = confidential;
-    }
-
-    @Override
-    public String toString() {
-        return (JacksonJson.toJsonString(this));
-    }
-}
+package org.gitlab4j.api.webhook;
+
+import java.util.Date;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.fasterxml.jackson.annotation.JsonAnyGetter;
+import com.fasterxml.jackson.annotation.JsonAnySetter;
+import org.gitlab4j.api.models.Assignee;
+import org.gitlab4j.api.utils.JacksonJson;
+
+public class EventChanges {
+
+    private ChangeContainer<String> state;
+    private ChangeContainer<Date> updatedAt;
+    private ChangeContainer<Integer> updatedById;
+    private ChangeContainer<Date> dueDate;
+    private ChangeContainer<Integer> milestoneId;
+    private ChangeContainer<List<EventLabel>> labels;
+    private ChangeContainer<List<Assignee>> assignees;
+    private ChangeContainer<Integer> totalTimeSpent;
+    private ChangeContainer<Boolean> confidential;
+    private LinkedHashMap<String, ChangeContainer<Object>> otherProperties = new LinkedHashMap<>();
+
+    public ChangeContainer<Date> getUpdatedAt() {
+        return updatedAt;
+    }
+
+    public void setUpdatedAt(ChangeContainer<Date> updatedAt) {
+        this.updatedAt = updatedAt;
+    }
+
+    public ChangeContainer<Integer> getUpdatedById() {
+        return updatedById;
+    }
+
+    public void setUpdatedById(ChangeContainer<Integer> updatedById) {
+        this.updatedById = updatedById;
+    }
+
+    public ChangeContainer<Date> getDueDate() {
+        return dueDate;
+    }
+
+    public void setDueDate(ChangeContainer<Date> dueDate) {
+        this.dueDate = dueDate;
+    }
+
+    public ChangeContainer<Integer> getMilestoneId() {
+        return milestoneId;
+    }
+
+    public void setMilestoneId(ChangeContainer<Integer> milestoneId) {
+        this.milestoneId = milestoneId;
+    }
+
+    public ChangeContainer<List<EventLabel>> getLabels() {
+        return labels;
+    }
+
+    public void setLabels(ChangeContainer<List<EventLabel>> labels) {
+        this.labels = labels;
+    }
+
+    public ChangeContainer<List<Assignee>> getAssignees() {
+        return assignees;
+    }
+
+    public void setAssignees(ChangeContainer<List<Assignee>> assignees) {
+        this.assignees = assignees;
+    }
+
+    public ChangeContainer<Integer> getTotalTimeSpent() {
+        return totalTimeSpent;
+    }
+
+    public void setTotalTimeSpent(ChangeContainer<Integer> totalTimeSpent) {
+        this.totalTimeSpent = totalTimeSpent;
+    }
+
+    public ChangeContainer<Boolean> getConfidential() {
+        return confidential;
+    }
+
+    public void setConfidential(ChangeContainer<Boolean> confidential) {
+        this.confidential = confidential;
+    }
+
+    public ChangeContainer<String> getState() {
+        return state;
+    }
+
+    public void setState(ChangeContainer<String> state) {
+        this.state = state;
+    }
+
+    public <T> ChangeContainer<T> get(String property){
+        if(otherProperties.containsKey(property)){
+            try {
+                final ChangeContainer<Object> container = otherProperties.get(property);
+                //noinspection unchecked It's duty from caller to be sure to do that
+                return container != null ? (ChangeContainer<T>) container : null;
+            } catch (ClassCastException e) {
+                return null;
+            }
+        } else {
+            return null;
+        }
+    }
+
+    @JsonAnyGetter
+    public Map<String, ChangeContainer<Object>> any() {
+        return this.otherProperties;
+    }
+
+    @JsonAnySetter
+    public void set(String name, ChangeContainer<Object> value) {
+        otherProperties.put(name, value);
+    }
+
+    @Override
+    public String toString() {
+        return (JacksonJson.toJsonString(this));
+    }
+}