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