add isFinished methods for chunks

Author: CJCrafter

src/main/kotlin/com/cjcrafter/openai/chat/ChatChoiceChunk.kt

@@ -37,6 +37,13 @@ data class ChatChoiceChunk(
         message.content += delta
         finishReason = if (json["finish_reason"].isJsonNull) null else FinishReason.valueOf(json["finish_reason"].asString.uppercase())
     }
+
+    /**
+     * Returns `true` if this message chunk is complete. Once complete, no more
+     * tokens will be generated, and [ChatChoiceChunk.message] will contain the
+     * complete message.
+     */
+    fun isFinished() = finishReason != null
 }
 
 /*

src/main/kotlin/com/cjcrafter/openai/completions/CompletionChoiceChunk.kt

@@ -1,6 +1,7 @@
 package com.cjcrafter.openai.completions
 
 import com.cjcrafter.openai.FinishReason
+import com.cjcrafter.openai.chat.ChatChoiceChunk
 import com.google.gson.annotations.SerializedName
 
 /**
@@ -25,4 +26,10 @@ data class CompletionChoiceChunk(
     val index: Int,
     val logprobs: List<Float>?,
     @field:SerializedName("finish_reason") val finishReason: FinishReason?
-)
+) {
+    /**
+     * Returns `true` if this message chunk is complete. Once complete, no more
+     * tokens will be generated.
+     */
+    fun isFinished() = finishReason != null
+}