code: 
  
  
  
  
  
  from __future__ import annotations
  
  from typing import Any
  
  
  
  
  class 				_lowerCamelCase :
  
  
  
        """simple docstring"""
  
  
  
  
  
  
        def __init__( self				,						UpperCAmelCase				,						UpperCAmelCase   )       ->   None:  # noqa: A002
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				List[Any]        =       item
          __snake_case   :				Any        =       next
  
  
  
  
  class 				_lowerCamelCase :
  
  
  
        """simple docstring"""
  
  
  
  
  
  
        def __init__( self   )       ->   None:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				Node | None        =       None
          __snake_case   :				Optional[Any]        =       0
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self				,						UpperCAmelCase   )       ->   None:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				Tuple        =       Node(UpperCAmelCase				,						self.head   )
          self.size += 1
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self   )       ->   Any:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          if self.head is None:
            return None
          else:
            __snake_case   :				Any        =       self.head.item
            __snake_case   :				int        =       self.head.next
            self.size -= 1
            return item
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self   )       ->   bool:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return self.head is None
  
  
  
  
  
  
  
        def __str__( self   )       ->   str:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          if self.is_empty():
            return ""
          else:
            __snake_case   :				Any        =       self.head
            __snake_case   :				int        =       ""
            __snake_case   :				list[str]        =       []
            while iterate:
              item_list.append(str(iterate.item   )   )
              __snake_case   :				Union[str, Any]        =       iterate.next
  
            __snake_case   :				List[str]        =       " --> ".join(UpperCAmelCase   )
  
            return item_str
  
  
  
  
  
  
  
        def __len__( self   )       ->   int:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return self.size
  
  
style_context: 
  
  
  
  
  
  from typing import TYPE_CHECKING
  
  from ...utils import OptionalDependencyNotAvailable, _LazyModule, is_torch_available
  
  
  _UpperCamelCase       = {'''configuration_nat''': ['''NAT_PRETRAINED_CONFIG_ARCHIVE_MAP''', '''NatConfig''']}
  
  
  try:
       if not is_torch_available():
            raise OptionalDependencyNotAvailable()
  except OptionalDependencyNotAvailable:
       pass
  else:
       _UpperCamelCase       = [
           '''NAT_PRETRAINED_MODEL_ARCHIVE_LIST''',
           '''NatForImageClassification''',
           '''NatModel''',
           '''NatPreTrainedModel''',
           '''NatBackbone''',
       ]
  
  if TYPE_CHECKING:
       from .configuration_nat import NAT_PRETRAINED_CONFIG_ARCHIVE_MAP, NatConfig
  
       try:
            if not is_torch_available():
                 raise OptionalDependencyNotAvailable()
       except OptionalDependencyNotAvailable:
            pass
       else:
            from .modeling_nat import (
                NAT_PRETRAINED_MODEL_ARCHIVE_LIST,
                NatBackbone,
                NatForImageClassification,
                NatModel,
                NatPreTrainedModel,
            )
  
  else:
       import sys
  
       _UpperCamelCase       = _LazyModule(__name__, globals()['''__file__'''], _import_structure, module_spec=__spec__)
  
  