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import abc

from dataclasses import dataclass, field

import os

import time

from dataclasses import (

    dataclass,

    field,

)

from typing import (

    Any,

    ClassVar,

    # the HTTPFilesSource passes in additional http_headers through these properties, which

    # are merged with constructor defined http_headers. The interpretation of these properties

    # are filesystem specific.

    extra_props: Optional[FilesSourceProperties] = field(default_factory=lambda: {})

    extra_props: Optional[FilesSourceProperties] = field(default_factory=lambda: FilesSourceProperties())

class SingleFileSource(metaclass=abc.ABCMeta):