


"""simple docstring"""







from __future__ import annotations

from collections.abc import Iterator
from typing import Any
class 							lowerCamelCase       :






							def __init__(						self :     str		, lowerCamelCase_ :     Any				):
													UpperCAmelCase__		=    data
													UpperCAmelCase__		=    None






							def __str__(						self :     Union[str, Any]				):
													return f"""{self.data}"""




class 							lowerCamelCase       :






							def __init__(						self :     Optional[int]				):
													UpperCAmelCase__		=    None
													UpperCAmelCase__		=    None






							def __iter__(						self :     str				):
													UpperCAmelCase__		=    self.front
													while node:
																			yield node.data
																			UpperCAmelCase__		=    node.next






							def __len__(						self :     Tuple				):
													return len(tuple(iter(self				)				)				)






							def __str__(						self :     Union[str, Any]				):
													return " <- ".join(str(lowerCamelCase_				) for item in self				)






							def 					lowerCAmelCase     (						self :     List[str]				):
													return len(self				) == 0






							def 					lowerCAmelCase     (						self :     Union[str, Any]		, lowerCamelCase_ :     Any				):
													UpperCAmelCase__		=    Node(lowerCamelCase_				)
													if self.is_empty():
																			UpperCAmelCase__		=    node
													else:
																			assert isinstance(self.rear		, lowerCamelCase_				)
																			UpperCAmelCase__		=    node
																			UpperCAmelCase__		=    node






							def 					lowerCAmelCase     (						self :     Dict				):






													if self.is_empty():
																			raise IndexError('''dequeue from empty queue'''				)
													assert isinstance(self.front		, lowerCamelCase_				)
													UpperCAmelCase__		=    self.front
													UpperCAmelCase__		=    self.front.next
													if self.front is None:
																			UpperCAmelCase__		=    None
													return node.data






							def 					lowerCAmelCase     (						self :     str				):
													UpperCAmelCase__		=    None


if __name__ == "__main__":
						from doctest import testmod

						testmod()



"""simple docstring"""







import safs
class 							lowerCamelCase       (			safs.SaFileSystem ):


							"""simple docstring"""