Improve some comments (#472)

Change-Id: I237f3e4175eec538aff01c521ec6e93cc8c2fc87

hugegraph-cassandra/src/main/java/com/baidu/hugegraph/backend/store/cassandra/CassandraShard.java

@@ -129,13 +129,13 @@ public class CassandraShard {
     /**
      * Get splits of a table in specified range
      * NOTE: maybe we don't need this method
-     * @param start, end: the specified range
+     * @param start: the start of range
+     * @param end: the end of range
      * @param splitPartitions: expected partitions count per split
      * @param splitSize: expected size(bytes) per split,
      *        splitPartitions will be ignored if splitSize is passed
      * @return a list of Shard
      */
-
     public List<Shard> getSplits(String start, String end,
                                  int splitPartitions, int splitSize) {
 

hugegraph-core/src/main/java/com/baidu/hugegraph/HugeGraph.java

@@ -186,9 +186,6 @@ public class HugeGraph implements GremlinGraph {
         return this.indexEventHub;
     }
 
-    /**
-     * @SuppressWarnings("UnstableApiUsage")
-     */
     public RateLimiter rateLimiter() {
         return this.rateLimiter;
     }
@@ -574,8 +571,7 @@ public class HugeGraph implements GremlinGraph {
 
     /**
      * Stop all the daemon threads
-     * @param timout seconds
-     * @throws InterruptedException when be interrupted
+     * @param timeout seconds
      */
     public static void shutdown(long timeout) {
         try {

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/page/IdHolder.java

@@ -38,6 +38,7 @@ public final class IdHolder {
 
     /**
      * For non-paging situation
+     * @param ids   all ids
      */
     public IdHolder(Set<Id> ids) {
         this.query = null;
@@ -52,6 +53,8 @@ public final class IdHolder {
 
     /**
      * For paging situation
+     * @param query         original query
+     * @param idsFetcher    function to fetch one page ids
      */
     public IdHolder(ConditionQuery query,
                     Function<ConditionQuery, PageIds> idsFetcher) {

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/tx/GraphIndexTransaction.java

@@ -141,6 +141,9 @@ public class GraphIndexTransaction extends AbstractTransaction {
 
     /**
      * Update index(user properties) of vertex or edge
+     * @param ilId      the id of index label
+     * @param element   the properties owner
+     * @param removed   remove or add index
      */
     protected void updateIndex(Id ilId, HugeElement element, boolean removed) {
         SchemaTransaction schema = graph().schemaTransaction();

hugegraph-core/src/main/java/com/baidu/hugegraph/job/schema/SchemaCallable.java

@@ -66,6 +66,8 @@ public abstract class SchemaCallable extends Job<Object> {
     /**
      * Use reflection to call SchemaTransaction.removeSchema(),
      * which is protected
+     * @param tx        The remove operation actual executer
+     * @param schema    the schema to be removed
      */
     protected static void removeSchema(SchemaTransaction tx,
                                        SchemaElement schema) {
@@ -86,6 +88,8 @@ public abstract class SchemaCallable extends Job<Object> {
     /**
      * Use reflection to call SchemaTransaction.updateSchema(),
      * which is protected
+     * @param tx        The update operation actual executer
+     * @param schema    the schema to be update
      */
     protected static void updateSchema(SchemaTransaction tx,
                                        SchemaElement schema) {

hugegraph-core/src/main/java/com/baidu/hugegraph/schema/PropertyKey.java

@@ -108,6 +108,7 @@ public class PropertyKey extends SchemaElement implements Propfiable {
     /**
      * Check type of the value valid
      * @param value the property value to be checked data type
+     * @param <V>   the property value original data type
      * @return true if the value is or can convert to the data type,
      *         otherwise false
      */

hugegraph-example/src/main/java/com/baidu/hugegraph/example/PerfExampleBase.java

@@ -89,7 +89,7 @@ public abstract class PerfExampleBase {
 
     /**
      * Multi-threaded and multi-commits and batch insertion test
-     * @param graph
+     * @param graph     graph
      * @param threadCount
      *        The count of threads that perform the insert operation at the
      *        same time
@@ -98,7 +98,7 @@ public abstract class PerfExampleBase {
      * @param multiple
      *        The coefficient to multiple number of vertices(100) and edges(100)
      *        for each transaction commit
-     * @throws InterruptedException
+     * @throws Exception    execute may throw Exception
      */
     public void testInsertPerf(GraphManager graph,
                                int threadCount,