diff --git a/src/main/kotlin/terminal/TerminalConfiguration.kt b/src/main/kotlin/terminal/TerminalConfiguration.kt
index d3b88a3..90615e9 100644
--- a/src/main/kotlin/terminal/TerminalConfiguration.kt
+++ b/src/main/kotlin/terminal/TerminalConfiguration.kt
@@ -13,7 +13,7 @@ class TerminalConfiguration {
     lateinit var inputReader: PipedInputStream
     lateinit var outputWriter: PipedOutputStream
     lateinit var outputReader: PipedInputStream
-    lateinit var terminal: IOSafeTerminal
+    var terminal: IOSafeTerminal? = null
 
     fun setInputPair(inputWriter: PipedOutputStream, inputReader: PipedInputStream) {
         this.inputWriter = inputWriter
diff --git a/src/main/kotlin/terminal/TerminalHistory.kt b/src/main/kotlin/terminal/TerminalHistory.kt
index f721d78..b246a39 100644
--- a/src/main/kotlin/terminal/TerminalHistory.kt
+++ b/src/main/kotlin/terminal/TerminalHistory.kt
@@ -1,29 +1,16 @@
 package terminal
 
-import java.util.ArrayList
-
 class TerminalHistory {
 
-    private val history: MutableList<String>
-    private var lineIndex: Int = 0
+    private val history = mutableListOf("")
+    private var lineIndex = 0
 
-    val previousLine: String
-        get() = if (isBeginning) history[lineIndex] else history[--lineIndex]
+    fun getPreviousLine() = if (isBeginning()) history[lineIndex] else history[--lineIndex]
+    fun getNextLine() = if (isEnd()) history[lineIndex] else history[++lineIndex]
+    fun isBeginning() = lineIndex == 0
+    fun isEnd() = lineIndex == lastIndex()
 
-    val isBeginning: Boolean
-        get() = lineIndex == 0
-
-    val nextLine: String
-        get() = if (isEnd) history[lineIndex] else history[++lineIndex]
-
-    val isEnd: Boolean
-        get() = lineIndex == lastIndex()
-
-    init {
-        this.history = ArrayList()
-        this.history.add("")
-        this.lineIndex = 0
-    }
+    private fun lastIndex() = history.size - 1
 
     fun addLine(line: String) {
         history[lastIndex()] = line
@@ -31,10 +18,6 @@ class TerminalHistory {
         lineIndex = lastIndex()
     }
 
-    private fun lastIndex(): Int {
-        return history.size - 1
-    }
-
     fun updateCurrentLine(line: String) {
         history[lineIndex] = line
     }