.DEVNULL: Int
.PIPE: Int
.STDOUT: Int

.SubprocessError: ClassType
.SubprocessError <: Exception

.TimeoutExpired: ClassType
.TimeoutExpired <: SubprocessError
.TimeoutExpired.
    cmd: Str
    timeout: Float
    output: Bytes or NoneType
    stdout: Bytes or NoneType
    stderr: Bytes or NoneType

.CalledProcessError: ClassType
.CalledProcessError <: SubprocessError
.CalledProcessError.
    cmd: Str or [Str; _]
    returncode: Int
    output: Bytes or NoneType
    stdout: Bytes or NoneType
    stderr: Bytes or NoneType

.CompletedProcess: ClassType
.CompletedProcess.
    args: Str or [Str; _]
    returncode: Int
    stdout: Bytes or NoneType
    stderr: Bytes or NoneType

.Popen: ClassType
.Popen.
    pid: Int
    stdin: File!
    stdout: File!
    stderr: File!
    __call__: (
        args: Iterable(Str),
        bufsize := Int,
        executable := Str,
        stdin := File! or Int or NoneType,
        stdout := File! or Int or NoneType,
        stderr := File! or Int or NoneType,
        preexec_fn := (() => NoneType) or NoneType,
        close_fds := Bool,
        shell := Bool,
        cwd := Str or NoneType,
        env := {Str: Str} or NoneType,
        universal_newlines := Bool,
        startupinfo := Obj,
        creationflags := Int,
        restore_signals := Bool,
        start_new_session := Bool,
        pass_fds := Iterable(Int),
        group := Int,
        extra_groups := Iterable(Int),
        user := Int,
        umask := Int,
        encoding := Str or NoneType,
        errors := Str or NoneType,
        text := Bool,
        pipesize := Int,
        process_group := Int,
    ) -> .Popen
    poll!: (self: .Popen) => Int or NoneType
    wait!: (self: .Popen, timeout := Float) => Int

.run!: (
    args: Str or [Str; _],
    stdin: File! or NoneType := NoneType,
    stdout: File! or NoneType := NoneType,
    stderr: File! or NoneType := NoneType,
    capture_output := Bool,
    shell := Bool,
) => .CompletedProcess
.call!: (
    args: Str or [Str; _],
    stdin: File! or NoneType := NoneType,
    stdout: File! or NoneType := NoneType,
    stderr: File! or NoneType := NoneType,
    shell := Bool,
) => Int
.check_call!: (
    args: Str or [Str; _],
    stdin: File! or NoneType := NoneType,
    stderr: File! or NoneType := NoneType,
    shell := Bool,
) => {0} or Never
.check_output!: (
    args: Str or [Str; _],
    stdin: File! or NoneType := NoneType,
    stderr: File! or NoneType := NoneType,
    shell := Bool,
) => Bytes or NoneType