Enable passing arguments to custom functions

api/src/main/kotlin/io/smnp/collection/Stack.kt

@@ -0,0 +1,25 @@
+package io.smnp.collection
+
+class Stack<T> private constructor(private val list: MutableList<T>) : List<T> by list {
+    fun push(item: T) {
+        list.add(item)
+    }
+
+    fun pop(): T? {
+        if(list.isEmpty()) {
+            return null
+        }
+
+        val last = list.last()
+        list.removeAt(list.size-1)
+        return last
+    }
+
+    fun top() = list.last()
+
+    companion object {
+        fun <T> of(vararg items: T): Stack<T> {
+            return Stack(mutableListOf(*items))
+        }
+    }
+}