diff --git a/lib/Util.dart b/lib/Util.dart
index 703601a..5065be9 100644
--- a/lib/Util.dart
+++ b/lib/Util.dart
@@ -1,4 +1,6 @@
-#library('Util');
+library Util;
+
+import 'dart:math';
 
 /**
  * Converts the byte sequence to a numeric representation.
@@ -7,7 +9,7 @@ bytesToValue(List<int> bytes) {
   var value = 0;
 
   for (var i = 0, length = bytes.length; i < length; i++) {
-    value += bytes[i] * Math.pow(256, i);
+    value += bytes[i] * pow(256, i);
   }
 
   return value;
diff --git a/lib/Zip.dart b/lib/Zip.dart
index a981fb5..77fefc7 100644
--- a/lib/Zip.dart
+++ b/lib/Zip.dart
@@ -6,12 +6,12 @@
  * http://www.opensource.org/licenses/mit-license.php
  */
 
-#library('Zip');
+library Zip;
 
-#import('dart:io');
-#import('EndOfCentralDirectoryRecord.dart');
-#import('CentralDirectory.dart');
-#import('Util.dart');
+import 'dart:io';
+import 'end_of_central_directory_record.dart';
+import 'central_directory.dart';
+import 'util.dart';
 
 /**
  * This class represents a Zip file.
@@ -30,6 +30,7 @@ class Zip {
   EndOfCentralDirectoryRecord _endOfCentralDirectoryRecord;
   CentralDirectory _centralDirectory;
   List files;
+  bool _initialized = false;
 
   Zip(Path this._filePath);
 
@@ -40,6 +41,7 @@ class Zip {
    */
   Future<Exception> open() {
     var completer = new Completer();
+    _initialized = true;
 
     this._file = new File.fromPath(this._filePath);
 
@@ -48,7 +50,7 @@ class Zip {
 
       try {
         this._process();
-      } catch (Exception e) {
+      } on Exception catch (e) {
         completer.completeException(e);
       }
 
@@ -90,7 +92,7 @@ class Zip {
     }
 
     // If the Zip is not yet opened, open it first before we can extract it.
-    if (this._centralDirectory == null) {
+    if (this._initialized == false) {
       this.open().then((error) {
 
         // Check for potential errors.
diff --git a/lib/CentralDirectory.dart b/lib/central_directory.dart
similarity index 76%
rename from lib/CentralDirectory.dart
rename to lib/central_directory.dart
index c065e39..f0d99b5 100644
--- a/lib/CentralDirectory.dart
+++ b/lib/central_directory.dart
@@ -6,11 +6,11 @@
  * http://www.opensource.org/licenses/mit-license.php
  */
 
-#library('CentralDirectory');
+library CentralDirectory;
 
-#import('Zip.dart');
-#import('CentralDirectoryFileHeader.dart');
-#import('Util.dart');
+import 'zip.dart';
+import 'central_directory_file_header.dart';
+import 'util.dart';
 
 /**
  * Creates a new instance of the Central Directory.
@@ -65,22 +65,22 @@ class CentralDirectory {
     // 	file comment (variable size)
 
     var position = 0;
-    var signatureSize = Zip.CENTRAL_DIRECTORY_FILE_HEADER_SIGNATURE.length;
-    var signatureCodes = Zip.CENTRAL_DIRECTORY_FILE_HEADER_SIGNATURE.charCodes();
+    final signatureSize = Zip.CENTRAL_DIRECTORY_FILE_HEADER_SIGNATURE.length;
+    final signatureCodes = Zip.CENTRAL_DIRECTORY_FILE_HEADER_SIGNATURE.charCodes();
 
     // Create file headers. Loop until we have gone through the entire buffer.
     while (true) {
       // Calculate sizes for dynamic parts.
-      var filenameSize = bytesToValue(this._chunk.getRange(28, 2));
-      var extraFieldSize = bytesToValue(this._chunk.getRange(30, 2));
-      var fileCommentSize = bytesToValue(this._chunk.getRange(32, 2));
+      final filenameSize = bytesToValue(this._chunk.getRange(28, 2));
+      final extraFieldSize = bytesToValue(this._chunk.getRange(30, 2));
+      final fileCommentSize = bytesToValue(this._chunk.getRange(32, 2));
 
-      var dynamicSize = filenameSize + fileCommentSize + extraFieldSize;
-      var totalFileHeaderSize = dynamicSize + FILE_HEADER_STATIC_SIZE;
+      final dynamicSize = filenameSize + fileCommentSize + extraFieldSize;
+      final totalFileHeaderSize = dynamicSize + FILE_HEADER_STATIC_SIZE;
 
       // Push a new file header.
       if (this._chunk.length >= position + totalFileHeaderSize) {
-        var buffer = this._chunk.getRange(position, totalFileHeaderSize);
+        final buffer = this._chunk.getRange(position, totalFileHeaderSize);
         this.fileHeaders.add(new CentralDirectoryFileHeader(buffer, this._data));
 
         // Move the position pointer forward.
diff --git a/lib/CentralDirectoryFileHeader.dart b/lib/central_directory_file_header.dart
similarity index 92%
rename from lib/CentralDirectoryFileHeader.dart
rename to lib/central_directory_file_header.dart
index ba626e1..6e08334 100644
--- a/lib/CentralDirectoryFileHeader.dart
+++ b/lib/central_directory_file_header.dart
@@ -6,12 +6,12 @@
  * http://www.opensource.org/licenses/mit-license.php
  */
 
-#library('CentralDirectoryFileHeader');
+library CentralDirectoryFileHeader;
 
-#import('Zip.dart');
-#import('Util.dart');
-#import('LocalFileHeader.dart');
-#import('dart:utf');
+import 'zip.dart';
+import 'util.dart';
+import 'local_file_header.dart';
+import 'dart:utf';
 
 /**
  * Creates a new instance of the Central Directory File Header.
@@ -93,7 +93,6 @@ class CentralDirectoryFileHeader {
     this.fileComment = this._chunk.getRange(46 + this.filenameLength + this.extraFieldLength, this.fileCommentLength);
 
     // TODO: Are there scenarios where LocalFileHeader.compressedSize != CentralDirectoryFileHeader.compressedSize?
-    print("offset ${this.localHeaderOffset}");
     this.localFileHeader = new LocalFileHeader(this._data.getRange(this.localHeaderOffset, this._data.length - this.localHeaderOffset));
   }
 }
\ No newline at end of file
diff --git a/lib/EndOfCentralDirectoryRecord.dart b/lib/end_of_central_directory_record.dart
similarity index 92%
rename from lib/EndOfCentralDirectoryRecord.dart
rename to lib/end_of_central_directory_record.dart
index be798b3..19b5e5f 100644
--- a/lib/EndOfCentralDirectoryRecord.dart
+++ b/lib/end_of_central_directory_record.dart
@@ -6,10 +6,10 @@
  * http://www.opensource.org/licenses/mit-license.php
  */
 
-#library('EndOfCentralDirectoryRecord');
+library EndOfCentralDirectoryRecord;
 
-#import('Zip.dart');
-#import('Util.dart');
+import 'zip.dart';
+import 'util.dart';
 
 /**
  * Creates a new instance of the End of Central Directory Record.
diff --git a/lib/LocalFileHeader.dart b/lib/local_file_header.dart
similarity index 93%
rename from lib/LocalFileHeader.dart
rename to lib/local_file_header.dart
index 681f0d2..e7a05cd 100644
--- a/lib/LocalFileHeader.dart
+++ b/lib/local_file_header.dart
@@ -6,11 +6,11 @@
  * http://www.opensource.org/licenses/mit-license.php
  */
 
-#library('LocalFileHeader');
+library LocalFileHeader;
 
-#import('Zip.dart');
-#import('Util.dart');
-#import('dart:utf');
+import 'zip.dart';
+import 'util.dart';
+import 'dart:utf';
 
 class LocalFileHeader {
   List<int> _chunk;
diff --git a/test/test.dart b/test/test.dart
index dd3a00e..594ee6a 100644
--- a/test/test.dart
+++ b/test/test.dart
@@ -1,8 +1,10 @@
-#import('../lib/Zip.dart');
-#import('dart:io');
+import '../lib/zip.dart';
+import 'dart:io';
 
 void main() {
-  var zip = new Zip(new Path('test.zip'));
+  final zip = new Zip(new Path('test.zip'));
+  //zip.addFileFromString('something.txt', 'content goes here');
+  //zip.save();
 
   zip.extractTo(new Path.fromNative("${new Directory.current().path}/test-extraction/"));