diff --git a/nd2reader/artificial.py b/nd2reader/artificial.py
index b69e9a1..861c613 100644
--- a/nd2reader/artificial.py
+++ b/nd2reader/artificial.py
@@ -6,6 +6,27 @@ import struct
 from nd2reader.common import check_or_make_dir
 from os import path
 
+global_labels = ['image_attributes', 'image_text_info', 'image_metadata',
+                 'image_metadata_sequence', 'image_calibration', 'x_data',
+                 'y_data', 'z_data', 'roi_metadata', 'pfs_status', 'pfs_offset',
+                 'guid', 'description', 'camera_exposure_time', 'camera_temp',
+                 'acquisition_times', 'acquisition_times_2',
+                 'acquisition_frames', 'lut_data', 'grabber_settings',
+                 'custom_data', 'app_info', 'image_frame_0']
+
+global_file_labels = ["ImageAttributesLV!", "ImageTextInfoLV!",
+                      "ImageMetadataLV!", "ImageMetadataSeqLV|0!",
+                      "ImageCalibrationLV|0!", "CustomData|X!", "CustomData|Y!",
+                      "CustomData|Z!", "CustomData|RoiMetadata_v1!",
+                      "CustomData|PFS_STATUS!", "CustomData|PFS_OFFSET!",
+                      "CustomData|GUIDStore!", "CustomData|CustomDescriptionV1_0!",
+                      "CustomData|Camera_ExposureTime1!", "CustomData|CameraTemp1!",
+                      "CustomData|AcqTimesCache!", "CustomData|AcqTimes2Cache!",
+                      "CustomData|AcqFramesCache!", "CustomDataVar|LUTDataV1_0!",
+                      "CustomDataVar|GrabberCameraSettingsV1_0!",
+                      "CustomDataVar|CustomDataV2_0!", "CustomDataVar|AppInfo_V1_0!",
+                      "ImageDataSeq|0!"]
+
 
 class ArtificialND2(object):
     """Artificial ND2 class (for testing purposes)
@@ -97,58 +118,6 @@ class ArtificialND2(object):
 
         return locations, data
 
-    @staticmethod
-    def _get_labels():
-        return ['image_attributes',
-                'image_text_info',
-                'image_metadata',
-                'image_metadata_sequence',
-                'image_calibration',
-                'x_data',
-                'y_data',
-                'z_data',
-                'roi_metadata',
-                'pfs_status',
-                'pfs_offset',
-                'guid',
-                'description',
-                'camera_exposure_time',
-                'camera_temp',
-                'acquisition_times',
-                'acquisition_times_2',
-                'acquisition_frames',
-                'lut_data',
-                'grabber_settings',
-                'custom_data',
-                'app_info',
-                'image_frame_0']
-
-    @staticmethod
-    def _get_file_labels():
-        return ["ImageAttributesLV!",
-                "ImageTextInfoLV!",
-                "ImageMetadataLV!",
-                "ImageMetadataSeqLV|0!",
-                "ImageCalibrationLV|0!",
-                "CustomData|X!",
-                "CustomData|Y!",
-                "CustomData|Z!",
-                "CustomData|RoiMetadata_v1!",
-                "CustomData|PFS_STATUS!",
-                "CustomData|PFS_OFFSET!",
-                "CustomData|GUIDStore!",
-                "CustomData|CustomDescriptionV1_0!",
-                "CustomData|Camera_ExposureTime1!",
-                "CustomData|CameraTemp1!",
-                "CustomData|AcqTimesCache!",
-                "CustomData|AcqTimes2Cache!",
-                "CustomData|AcqFramesCache!",
-                "CustomDataVar|LUTDataV1_0!",
-                "CustomDataVar|GrabberCameraSettingsV1_0!",
-                "CustomDataVar|CustomDataV2_0!",
-                "CustomDataVar|AppInfo_V1_0!",
-                "ImageDataSeq|0!"]
-
     def create_label_map_bytes(self):
         """Construct a binary label map
 
@@ -157,8 +126,8 @@ class ArtificialND2(object):
 
         """
         raw_text = six.b('')
-        labels = self._get_labels()
-        file_labels = self._get_file_labels()
+        labels = global_labels
+        file_labels = global_file_labels
 
         file_data, file_data_dict = self._get_file_data(labels)