[Improvement-17057][Master]Check if the WorkflowGrapth is a dag at constructor(#17057)

Author: yingh0ng

dolphinscheduler-master/src/main/java/org/apache/dolphinscheduler/server/master/engine/graph/WorkflowGraph.java

@@ -17,6 +17,8 @@
 
 package org.apache.dolphinscheduler.server.master.engine.graph;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import org.apache.dolphinscheduler.dao.entity.TaskDefinition;
 import org.apache.dolphinscheduler.dao.entity.WorkflowTaskRelation;
 
@@ -31,8 +33,6 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 public class WorkflowGraph implements IWorkflowGraph {
 
     private final Map<Long, TaskDefinition> taskDefinitionCodeMap;

dolphinscheduler-master/src/test/java/org/apache/dolphinscheduler/server/master/engine/graph/WorkflowGraphCheckIfDAGTest.java

@@ -17,7 +17,6 @@
 
 package org.apache.dolphinscheduler.server.master.engine.graph;
 
-
 import org.apache.dolphinscheduler.dao.entity.TaskDefinition;
 import org.apache.dolphinscheduler.dao.entity.WorkflowTaskRelation;