Fixed bug with WordItem's time

app/src/main/java/com/paktalin/vocabularynotebook/firestoreitems/WordItem.kt

+package com.paktalin.vocabularynotebook.firestoreitems
+
+import android.util.Log
+import com.paktalin.vocabularynotebook.appsetup.ConfiguredFirestore
+
+import java.io.Serializable
+import java.util.Date
+
+class WordItem(word: String, translation: String, time: Date?, var id: String, private val vocabularyId: String) : Serializable {
+    var pojo: Pojo = Pojo(word, translation, time)
+
+    class Pojo(var word: String, var translation: String, var time:Date?) : Serializable {
+        init {
+            if (time == null) time = Date(System.currentTimeMillis())
+        }
+
+        fun print(): String {
+            return "word: $word; translation: $translation; time: $time"
+        }
+    }
+
+    constructor(pojo: Pojo, id: String, vocabularyId: String)
+            : this(pojo.word, pojo.translation, pojo.time, id, vocabularyId)
+
+    fun delete() {
+        ConfiguredFirestore.instance.collection("vocabularies").document(vocabularyId)
+                .collection("words").document(id).delete()
+                .addOnSuccessListener { Log.i(TAG, "Successfully deleted word with id $id") }
+                .addOnFailureListener { e -> Log.w(TAG, "deleteWordWithId $id:failure", e.fillInStackTrace()) }
+    }
+
+    companion object { private val TAG = "VN/" + WordItem::class.java.simpleName }
+}