diff --git a/pom.xml b/pom.xml
index 47d244b..5f2a600 100644
--- a/pom.xml
+++ b/pom.xml
@@ -45,6 +45,8 @@
             <optional>true</optional>
         </dependency>
 
+        <!-- Test dependencies -->
+
         <dependency>
             <groupId>ch.qos.logback</groupId>
             <artifactId>logback-classic</artifactId>
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/util/PagingAndSortingQueryParams.java b/src/main/java/xyz/zhouxy/plusone/commons/util/PagingAndSortingQueryParams.java
index ab712f6..4f4f5bb 100644
--- a/src/main/java/xyz/zhouxy/plusone/commons/util/PagingAndSortingQueryParams.java
+++ b/src/main/java/xyz/zhouxy/plusone/commons/util/PagingAndSortingQueryParams.java
@@ -20,7 +20,6 @@ import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.regex.Pattern;
 
 import javax.annotation.Nullable;
@@ -60,10 +59,9 @@ public class PagingAndSortingQueryParams {
     public PagingAndSortingQueryParams(Map<String, String> sortableProperties) {
         Preconditions.checkArgument(sortableProperties != null && !sortableProperties.isEmpty(),
                 "Sortable properties can not be empty.");
-        for (Entry<String, String> p : sortableProperties.entrySet()) {
-            Preconditions.checkArgument(StringUtils.isNotBlank(p.getKey()) && StringUtils.isNotBlank(p.getValue()),
-                    "Property name must not be blank.");
-        }
+        sortableProperties.forEach((k, v) -> 
+                Preconditions.checkArgument(StringUtils.isNotBlank(k) && StringUtils.isNotBlank(v),
+                "Property name must not be blank."));
         this.sortableProperties = ImmutableMap.copyOf(sortableProperties);
     }
 
diff --git a/src/test/java/xyz/zhouxy/plusone/commons/util/TreeBuilderTests.java b/src/test/java/xyz/zhouxy/plusone/commons/util/TreeBuilderTests.java
index 7b7b842..a1f56f6 100644
--- a/src/test/java/xyz/zhouxy/plusone/commons/util/TreeBuilderTests.java
+++ b/src/test/java/xyz/zhouxy/plusone/commons/util/TreeBuilderTests.java
@@ -124,10 +124,8 @@ class MenuList extends Menu {
     }
 
     static MenuList of(String parentMenuCode, String menuCode, String title, Iterable<Menu> children, int orderNum) {
-        MenuList instance = of(parentMenuCode, menuCode, title, orderNum);
-        for (Menu child : children) {
-            instance.addChild(child);
-        }
+        final MenuList instance = of(parentMenuCode, menuCode, title, orderNum);
+        children.forEach(instance::addChild);
         return instance;
     }