def  UpperCamelCase__						(				A__    )   ->					str:
				if not head:
								return True
				# split the list to two parts
				snake_case__							,  snake_case__					:	Optional[int]												=      head.next, head
				while fast and fast.next:
								snake_case__					:	List[Any]												=      fast.next.next
								snake_case__					:	Dict												=      slow.next
				snake_case__					:	Optional[int]												=      slow.next
				snake_case__					:	int												=      None  # Don't forget here! But forget still works!
				# reverse the second part
				snake_case__					:	Optional[int]												=      None
				while second:
								snake_case__					:	Union[str, Any]												=      second.next
								snake_case__					:	Union[str, Any]												=      node
								snake_case__					:	Optional[Any]												=      second
								snake_case__					:	List[Any]												=      nxt
				# compare two parts
				# second part has the same or one less node
				while node:
								if node.val != head.val:
												return False
								snake_case__					:	int												=      node.next
								snake_case__					:	Optional[Any]												=      head.next
				return True
def  UpperCamelCase__						(				A__    )   ->					int:
				if not head or not head.next:
								return True

				# 1. Get the midpoint (slow)
				snake_case__					:	Any												=      head
				while fast and fast.next:
								snake_case__							,  snake_case__					:	List[Any]												=      fast.next.next, slow.next

				# 2. Push the second half into the stack
				snake_case__					:	Dict												=      [slow.val]
				while slow.next:
								snake_case__					:	List[str]												=      slow.next
								stack.append(slow.val    )

				# 3. Comparison
				while stack:
								if stack.pop() != cur.val:
												return False
								snake_case__					:	int												=      cur.next

				return True

def  UpperCamelCase__						(				A__    )   ->					List[str]:
				if not head or not head.next:
								return True
				snake_case__					:	List[str]												=      {}
				snake_case__					:	List[str]												=      0
				while head:
								if head.val in d:
												d[head.val].append(__UpperCamelCase    )
								else:
												snake_case__					:	Optional[int]												=      [pos]
								snake_case__					:	Any												=      head.next
								pos += 1
				snake_case__					:	Tuple												=      pos - 1
				snake_case__					:	int												=      0
				for v in d.values():
								if len(__UpperCamelCase    ) % 2 != 0:
												middle += 1
								else:
												snake_case__					:	Any												=      0
												for i in range(0			, len(__UpperCamelCase    )    ):
																if v[i] + v[len(__UpperCamelCase    ) - 1 - step] != checksum:
																				return False
																step += 1
								if middle > 1:
												return False
				return True



import contextlib
import importlib
import io
import unittest

import transformers

# Try to import everything from transformers to ensure every object can be loaded.
from transformers import *  # noqa F406
from transformers.testing_utils import DUMMY_UNKNOWN_IDENTIFIER, require_flax, require_tf, require_torch
from transformers.utils import ContextManagers, find_labels, is_flax_available, is_tf_available, is_torch_available


if is_torch_available():
      from transformers import BertForPreTraining, BertForQuestionAnswering, BertForSequenceClassification

if is_tf_available():
      from transformers import TFBertForPreTraining, TFBertForQuestionAnswering, TFBertForSequenceClassification

if is_flax_available():
      from transformers import FlaxBertForPreTraining, FlaxBertForQuestionAnswering, FlaxBertForSequenceClassification


A   :     Tuple       =				DUMMY_UNKNOWN_IDENTIFIER
# An actual model hosted on huggingface.co

A   :     Dict       =				"main"
# Default branch name
A   :     List[str]       =				"f2c752cfc5c0ab6f4bdec59acea69eefbee381c2"
# One particular commit (not the top of `main`)
A   :     Tuple       =				"aaaaaaa"
# This commit does not exist, so we should 404.

A   :     int       =				"d9e9f15bc825e4b2c9249e9578f884bbcb5e3684"
# Sha-1 of config.json on the top of `main`, for checking purposes
A   :     Tuple       =				"4b243c475af8d0a7754e87d7d096c92e5199ec2fe168a2ee7998e3b8e9bcb1d3"


@contextlib.contextmanager
def    a__       (						):
      print("Welcome!" )
      yield
      print("Bye!" )


@contextlib.contextmanager
def    a__       (						):
      print("Bonjour!" )
      yield
      print("Au revoir!" )


class      lowerCamelCase    (unittest.TestCase    ):
  """simple docstring"""







  def       __A   (							self       :				Union[str, Any]      )     ->		Any:
        # If the spec is missing, importlib would not be able to import the module dynamically.
        assert transformers.__spec__ is not None
        assert importlib.util.find_spec("transformers"      ) is not None



class      lowerCamelCase    (unittest.TestCase    ):
  """simple docstring"""







  @unittest.mock.patch("sys.stdout"     ,   new_callable=io.StringIO      )
  def       __A   (							self       :				Tuple     ,   __magic_name__       :				Union[str, Any]      )     ->		Union[str, Any]:
        with ContextManagers([]      ):
              print("Transformers are awesome!"      )
        # The print statement adds a new line at the end of the output
        self.assertEqual(mock_stdout.getvalue()     ,   "Transformers are awesome!\n"      )







  @unittest.mock.patch("sys.stdout"     ,   new_callable=io.StringIO      )
  def       __A   (							self       :				Dict     ,   __magic_name__       :				Union[str, Any]      )     ->		int:
        with ContextManagers([context_en()]      ):
              print("Transformers are awesome!"      )
        # The output should be wrapped with an English welcome and goodbye
        self.assertEqual(mock_stdout.getvalue()     ,   "Welcome!\nTransformers are awesome!\nBye!\n"      )







  @unittest.mock.patch("sys.stdout"     ,   new_callable=io.StringIO      )
  def       __A   (							self       :				Tuple     ,   __magic_name__       :				str      )     ->		Union[str, Any]:
        with ContextManagers([context_fr(), context_en()]      ):
              print("Transformers are awesome!"      )
        # The output should be wrapped with an English and French welcome and goodbye
        self.assertEqual(mock_stdout.getvalue()     ,   "Bonjour!\nWelcome!\nTransformers are awesome!\nBye!\nAu revoir!\n"      )







  @require_torch
  def       __A   (							self       :				List[str]      )     ->		Union[str, Any]:
        self.assertEqual(find_labels(__magic_name__      )     ,   ["labels"]      )
        self.assertEqual(find_labels(__magic_name__      )     ,   ["labels", "next_sentence_label"]      )
        self.assertEqual(find_labels(__magic_name__      )     ,   ["start_positions", "end_positions"]      )


        class      lowerCamelCase    (SCREAMING_SNAKE_CASE__    ):
          """simple docstring"""







          pass



        self.assertEqual(find_labels(__magic_name__      )     ,   ["labels"]      )







  @require_tf
  def       __A   (							self       :				List[str]      )     ->		Optional[Any]:
        self.assertEqual(find_labels(__magic_name__      )     ,   ["labels"]      )
        self.assertEqual(find_labels(__magic_name__      )     ,   ["labels", "next_sentence_label"]      )
        self.assertEqual(find_labels(__magic_name__      )     ,   ["start_positions", "end_positions"]      )


        class      lowerCamelCase    (SCREAMING_SNAKE_CASE__    ):
          """simple docstring"""







          pass



        self.assertEqual(find_labels(__magic_name__      )     ,   ["labels"]      )







  @require_flax
  def       __A   (							self       :				int      )     ->		Tuple:
        # Flax models don't have labels
        self.assertEqual(find_labels(__magic_name__      )     ,   []      )
        self.assertEqual(find_labels(__magic_name__      )     ,   []      )
        self.assertEqual(find_labels(__magic_name__      )     ,   []      )


        class      lowerCamelCase    (SCREAMING_SNAKE_CASE__    ):
          """simple docstring"""







          pass



        self.assertEqual(find_labels(__magic_name__      )     ,   []      )


