Seperate Constants.java into some SubConstants Class - step 1 (#4017)

see #3137

Author: beiwei30

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/loadbalance/ConsistentHashLoadBalance.java

@@ -31,15 +31,22 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
-import static org.apache.dubbo.common.Constants.HASH_ARGUMENTS;
-import static org.apache.dubbo.common.Constants.HASH_NODES;
-
 /**
  * ConsistentHashLoadBalance
  */
 public class ConsistentHashLoadBalance extends AbstractLoadBalance {
     public static final String NAME = "consistenthash";
 
+    /**
+     * Hash nodes name
+     */
+    public static final String HASH_NODES = "hash.nodes";
+
+    /**
+     * Hash arguments name
+     */
+    public static final String HASH_ARGUMENTS = "hash.arguments";
+
     private final ConcurrentMap<String, ConsistentHashSelector<?>> selectors = new ConcurrentHashMap<String, ConsistentHashSelector<?>>();
 
     @SuppressWarnings("unchecked")