diff --git a/test/test_pipeline_sample.py b/test/test_pipeline_sample.py
index f3e9b22..7110fba 100644
--- a/test/test_pipeline_sample.py
+++ b/test/test_pipeline_sample.py
@@ -1,16 +1,10 @@
-from arekit.common.pipeline.items.base import BasePipelineItem
-from arekit.common.utils import split_by_whitespaces
-
 import utils
 import unittest
-import ru_sent_tokenize
 
-from ru_sent_tokenize import ru_sent_tokenize
 from os.path import join
 
-from arekit.common.docs.base import Document
+from arekit.common.utils import split_by_whitespaces
 from arekit.common.docs.entities_grouping import EntitiesGroupingPipelineItem
-from arekit.common.docs.sentence import BaseDocumentSentence
 from arekit.common.experiment.data_type import DataType
 from arekit.common.labels.base import NoLabel
 from arekit.common.labels.scaler.single import SingleLabelScaler
@@ -18,6 +12,7 @@
 from arekit.common.synonyms.grouping import SynonymsCollectionValuesGroupingProviders
 from arekit.common.data import const
 from arekit.common.pipeline.context import PipelineContext
+from arekit.common.pipeline.items.base import BasePipelineItem
 from arekit.contrib.utils.data.writers.sqlite_native import SQliteWriter
 from arekit.contrib.utils.processing.lemmatization.mystem import MystemWrapper
 from arekit.contrib.utils.synonyms.stemmer_based import StemmerBasedSynonymCollection
@@ -49,16 +44,6 @@ class BertTestSerialization(unittest.TestCase):
         model.
     """
 
-    @staticmethod
-    def input_to_docs(texts):
-        docs = []
-        for doc_id, contents in enumerate(texts):
-            sentences = ru_sent_tokenize(contents)
-            sentences = list(map(lambda text: BaseDocumentSentence(text), sentences))
-            doc = Document(doc_id=doc_id, sentences=sentences)
-            docs.append(doc)
-        return docs
-
     @staticmethod
     def iter_groups(filepath):
         with open(filepath, 'r', encoding='utf-8') as file:
@@ -95,7 +80,7 @@ def test(self):
         ]
 
         # Composing labels formatter and experiment preparation.
-        doc_provider = utils.InMemoryDocProvider(docs=BertTestSerialization.input_to_docs(texts))
+        doc_provider = utils.InMemoryDocProvider(docs=utils.input_to_docs(texts))
         pipeline = [
             AREkitSerializerPipelineItem(
                 rows_provider=create_bert_sample_provider(