diff --git a/src/main/kotlin/conf/Clash.kt b/src/main/kotlin/conf/Clash.kt
index 2265617..28ccd68 100644
--- a/src/main/kotlin/conf/Clash.kt
+++ b/src/main/kotlin/conf/Clash.kt
@@ -910,7 +910,7 @@ data class Clash(
             override val dialerProxy: String? = null,
             override val healthCheck: HealthCheck? = null,
             override val override: Override? = null,
-            val url: String? = null, // Changed from non-nullable to nullable
+            val url: String? = null,
             val path: String? = null,
             val proxy: String? = null,
             val sizeLimit: Long? = null,
@@ -929,9 +929,9 @@ data class Clash(
         ) : ProxyProvider()
 
         data class HealthCheck(
-            val enable: Boolean? = null, // Changed from non-nullable to nullable
-            val url: String? = null, // Changed from non-nullable to nullable
-            val interval: Int? = null, // Changed from non-nullable to nullable
+            val enable: Boolean? = null,
+            val url: String? = null,
+            val interval: Int? = null,
             val timeout: Int? = null,
             val lazy: Boolean? = null,
             val expectedStatus: String? = null,
diff --git a/src/main/kotlin/util/JacksonUtil.kt b/src/main/kotlin/util/JacksonUtil.kt
index 352bf29..8302449 100644
--- a/src/main/kotlin/util/JacksonUtil.kt
+++ b/src/main/kotlin/util/JacksonUtil.kt
@@ -1,7 +1,6 @@
 package util
 
 import com.fasterxml.jackson.databind.JsonNode
-import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.databind.node.ArrayNode
 import com.fasterxml.jackson.databind.node.JsonNodeFactory
 import com.fasterxml.jackson.databind.node.ObjectNode
@@ -14,5 +13,4 @@ fun newArrayNode(list: List<JsonNode>): ArrayNode = JsonNodeFactory.instance.arr
 
 fun newTextNode(text: String): TextNode = JsonNodeFactory.instance.textNode(text)
 
-
 fun newObjectNode(map: Map<String, JsonNode>): ObjectNode = JsonNodeFactory.instance.objectNode().apply { map.forEach { replace(it.key, it.value) } }
\ No newline at end of file