Add contract

mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/utils/inline.kt

 package net.mamoe.mirai.qqandroid.utils
 
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
+
 /**
  * Inline the block
  */
+@UseExperimental(ExperimentalContracts::class)
 @PublishedApi
-internal inline fun <R> inline(block: () -> R): R = block()
\ No newline at end of file
+internal inline fun <R> inline(block: () -> R): R {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    return block()
+}
\ No newline at end of file