diff --git a/qurator/eynollah/eynollah.py b/qurator/eynollah/eynollah.py
index da3385f..fce73b5 100644
--- a/qurator/eynollah/eynollah.py
+++ b/qurator/eynollah/eynollah.py
@@ -8,11 +8,10 @@ document layout analysis (segmentation) with output in PAGE-XML
 
 from logging import Logger
 import math
-import os
-import sys
+from os import listdir
+from os.path import join
 import time
 from typing import Optional
-import warnings
 from pathlib import Path
 from multiprocessing import Process, Queue, cpu_count
 from PIL.Image import Image
@@ -23,19 +22,7 @@ from scipy.signal import find_peaks
 import matplotlib.pyplot as plt
 from scipy.ndimage import gaussian_filter1d
 
-from qurator.eynollah.utils.keras import PatchEncoder, Patches
-
-os.environ["TF_CPP_MIN_LOG_LEVEL"] = "3"
-stderr = sys.stderr
-sys.stderr = open(os.devnull, "w")
-import tensorflow as tf
-sys.stderr = stderr
-tf.get_logger().setLevel("ERROR")
-warnings.filterwarnings("ignore")
-
-load_model = tf.keras.models.load_model
-# use tf1 compatibility for keras backend
-set_session = tf.compat.v1.keras.backend.set_session
+from qurator.eynollah.utils.tf import tf, PatchEncoder, Patches
 
 from .utils.contour import (
     filter_contours_area_of_image,
@@ -182,7 +169,7 @@ class Eynollah():
             self.model_textline_dir = dir_models + "/eynollah-textline_20210425"
         self.model_tables = dir_models + "/eynollah-tables_20210319"
         
-        self.models = {}
+        self.models : dict[str, tf.keras.Model] = {}
         
         if dir_in and light_version:
             config = tf.compat.v1.ConfigProto()
@@ -198,7 +185,7 @@ class Eynollah():
             self.model_region_fl_np = self.our_load_model(self.model_region_dir_fully_np)
             self.model_region_fl = self.our_load_model(self.model_region_dir_fully)
             
-            self.ls_imgs  = os.listdir(self.dir_in)
+            self.ls_imgs  = listdir(self.dir_in)
             
         if dir_in and not light_version:
             config = tf.compat.v1.ConfigProto()
@@ -216,7 +203,7 @@ class Eynollah():
             self.model_region_fl = self.our_load_model(self.model_region_dir_fully)
             self.model_enhancement = self.our_load_model(self.model_dir_of_enhancement)
             
-            self.ls_imgs  = os.listdir(self.dir_in)
+            self.ls_imgs  = listdir(self.dir_in)
             
         
     def _cache_images(self, image_filename=None, image_pil=None):
@@ -586,9 +573,8 @@ class Eynollah():
         self.writer.scale_x = self.scale_x
         self.writer.height_org = self.height_org
         self.writer.width_org = self.width_org
-
     
-    def start_new_session_and_model(self, model_dir):
+    def start_new_session_and_model(self, model_dir) -> tf.keras.Model:
         self.logger.debug("enter start_new_session_and_model (model_dir=%s)", model_dir)
         #gpu_options = tf.compat.v1.GPUOptions(allow_growth=True)
         #gpu_options = tf.compat.v1.GPUOptions(per_process_gpu_memory_fraction=7.7, allow_growth=True)
@@ -613,8 +599,7 @@ class Eynollah():
                 model = load_model(model_dir , compile=False, custom_objects = {"PatchEncoder": PatchEncoder, "Patches": Patches})
                 self.models[model_dir] = model
 
-        # FIXME: why?
-        return model, None
+        return model
 
     def do_prediction(self, patches, img, model, marginal_of_patch_percent=0.1):
         self.logger.debug("enter do_prediction")
@@ -910,7 +895,7 @@ class Eynollah():
             img = cv2.GaussianBlur(self.image, (5, 5), 0)
             
             if not self.dir_in:
-                model_page, session_page = self.start_new_session_and_model(self.model_page_dir)
+                model_page = self.start_new_session_and_model(self.model_page_dir)
                 
             if not self.dir_in:
                 img_page_prediction = self.do_prediction(False, img, model_page)
@@ -958,7 +943,7 @@ class Eynollah():
             else:
                 img = self.imread()
             if not self.dir_in:
-                model_page, session_page = self.start_new_session_and_model(self.model_page_dir)
+                model_page = self.start_new_session_and_model(self.model_page_dir)
             img = cv2.GaussianBlur(img, (5, 5), 0)
             
             if self.dir_in:
@@ -2774,7 +2759,7 @@ class Eynollah():
         for img_name in self.ls_imgs:
             t0 = time.time()
             if self.dir_in:
-                self.reset_file_name_dir(os.path.join(self.dir_in,img_name))
+                self.reset_file_name_dir(join(self.dir_in,img_name))
             
             img_res, is_image_enhanced, num_col_classifier, num_column_is_classified = self.run_enhancement(self.light_version)
             self.logger.info("Enhancing took %.1fs ", time.time() - t0)
diff --git a/qurator/eynollah/utils/keras.py b/qurator/eynollah/utils/tf.py
similarity index 75%
rename from qurator/eynollah/utils/keras.py
rename to qurator/eynollah/utils/tf.py
index f5da4d2..546f05d 100644
--- a/qurator/eynollah/utils/keras.py
+++ b/qurator/eynollah/utils/tf.py
@@ -1,10 +1,37 @@
+import warnings
+from os import environ, devnull
+import sys
+
+environ["TF_CPP_MIN_LOG_LEVEL"] = "3"
+stderr = sys.stderr
+sys.stderr = open(devnull, "w")
 import tensorflow as tf
+sys.stderr = stderr
+tf.get_logger().setLevel("ERROR")
+warnings.filterwarnings("ignore")
+
 layers = tf.keras.layers
 
+__all__ = [
+    'PatchEncoder',
+    'Patches',
+    'load_model',
+    'set_session',
+    'tf',
+]
+
 PROJECTION_DIM = 64
 PATCH_SIZE = 1
 NUM_PATCHES = 21*21 #14*14#28*28#14*14#28*28
 
+def load_model(*args, **kwargs) -> tf.keras.Model:
+    ret = tf.keras.models.load_model(*args, **kwargs)
+    assert isinstance(ret, tf.keras.Model)
+    return ret
+
+# use tf1 compatibility for keras backend
+set_session = tf.compat.v1.keras.backend.set_session
+
 class Patches(layers.Layer):
 
     def __init__(self, *args, **kwargs):
@@ -55,4 +82,3 @@ class PatchEncoder(layers.Layer):
         })
         return config
 
-