diff --git a/Sources/MaxMindDBReader/MaxMindIterator.swift b/Sources/MaxMindDBReader/MaxMindIterator.swift
new file mode 100644
index 0000000..49ba3ed
--- /dev/null
+++ b/Sources/MaxMindDBReader/MaxMindIterator.swift
@@ -0,0 +1,21 @@
+//
+// Created by Rocska Ádám on 2020. 05. 04..
+//
+
+import Foundation
+
+class MaxMindIterator {
+  private let data:    Data
+  private var pointer: Data.Index
+
+  init?(_ data: Data) {
+    if data.isEmpty { return nil }
+    self.data = data
+    self.pointer = data.startIndex
+  }
+
+  func nextControlByte() -> ControlByte? {
+    return nil
+  }
+
+}
diff --git a/Tests/MaxMindDBReaderTests/MaxMindIteratorTest.swift b/Tests/MaxMindDBReaderTests/MaxMindIteratorTest.swift
new file mode 100644
index 0000000..29727cd
--- /dev/null
+++ b/Tests/MaxMindDBReaderTests/MaxMindIteratorTest.swift
@@ -0,0 +1,18 @@
+import Foundation
+import XCTest
+@testable import MaxMindDBReader
+
+class MaxMindIteratorTest: XCTestCase {
+
+  func testInit_returnsNilIfDataIsEmpty() {
+    XCTAssertNil(MaxMindIterator(Data()))
+  }
+
+  func testNextControlByte_noneDefined() {
+    let iterator = MaxMindIterator(Data(count: 150))
+    for _ in 0..<200 {
+      XCTAssertNil(iterator?.nextControlByte())
+    }
+  }
+
+}