diff --git a/src/main/java/xyz/zhouxy/plusone/commons/util/EnumUtil.java b/src/main/java/xyz/zhouxy/plusone/commons/util/EnumUtil.java
index 1d3091f..1d250df 100644
--- a/src/main/java/xyz/zhouxy/plusone/commons/util/EnumUtil.java
+++ b/src/main/java/xyz/zhouxy/plusone/commons/util/EnumUtil.java
@@ -46,7 +46,7 @@ public final class EnumUtil {
     public static <E extends Enum<?>> E valueOf(Class<E> clazz, int ordinal) {
         Preconditions.checkNotNull(clazz, "Clazz must not be null.");
         E[] values = clazz.getEnumConstants();
-        PreconditionsExt.isTrue((ordinal >= 0 && ordinal < values.length),
+        PreconditionsExt.check((ordinal >= 0 && ordinal < values.length),
                 () -> new EnumConstantNotPresentException(clazz, Integer.toString(ordinal)));
         return values[ordinal];
     }
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/util/PreconditionsExt.java b/src/main/java/xyz/zhouxy/plusone/commons/util/PreconditionsExt.java
index 6726233..909dfbb 100644
--- a/src/main/java/xyz/zhouxy/plusone/commons/util/PreconditionsExt.java
+++ b/src/main/java/xyz/zhouxy/plusone/commons/util/PreconditionsExt.java
@@ -18,9 +18,16 @@ package xyz.zhouxy.plusone.commons.util;
 
 import java.util.function.Supplier;
 
+/**
+ * Guava Preconditions 的扩展。
+ * 
+ * @author ZhouXY
+ * 
+ * @see com.google.common.base.Preconditions
+ */
 public class PreconditionsExt {
 
-    public static <E extends Throwable> void isTrue(boolean condition, Supplier<E> e) throws E {
+    public static <E extends Throwable> void check(boolean condition, Supplier<E> e) throws E {
         if (!condition) {
             throw e.get();
         }