Fix(client): fixed clearGraph apis

Author: sadwitdastreetz

hugegraph-client/src/main/java/org/apache/hugegraph/api/graphs/GraphsAPI.java

@@ -136,8 +136,17 @@ public void clear(String graph, boolean clearSchema) {
     }
 
     public void clear(String graph, String message) {
-        this.client.delete(joinPath(this.path(), graph, CLEAR),
-                           ImmutableMap.of(CONFIRM_MESSAGE, message));
+        clear(null, graph, message);
+    }
+
+    public void clear(String graphSpace, String graph, String message) {
+        if (graphSpace == null) {
+            this.client.delete(joinPath(this.path(), graph, CLEAR),
+                               ImmutableMap.of(CONFIRM_MESSAGE, message));
+        } else {
+            this.client.delete(joinPath(this.path(), graphSpace, graph, CLEAR),
+                               ImmutableMap.of(CONFIRM_MESSAGE, message));
+        }
     }
 
     public Map<String, String> update(String name, String nickname) {

hugegraph-client/src/main/java/org/apache/hugegraph/driver/GraphsManager.java

@@ -94,6 +94,10 @@ public void clearGraph(String graph, String message) {
         this.graphsAPI.clear(graph, message);
     }
 
+    public void clearGraph(String graphSpace, String graph, String message) {
+        this.graphsAPI.clear(graphSpace, graph, message);
+    }
+
     public void update(String graph, String nickname) {
         this.graphsAPI.update(graph, nickname);
     }