.Error = 'error': ClassType
.Error <: Exception

.Struct: ClassType
.Struct.
    __call__: (format: Str) -> .Struct
    format: Str
    size: Nat
    pack: (self: .Struct, *values: Obj) -> Bytes
    pack_into!: (self: .Struct, buffer: RefMut(ByteArray!), offset: Nat, *values: Obj) => NoneType
    unpack: (self: .Struct, buffer: Bytes) -> Obj
    unpack_from: (self: .Struct, buffer: Bytes, offset := Nat) -> [Obj; _]
    iter_unpack: (self: .Struct, buffer: Bytes) -> Iterator [Obj; _]

.pack: (format: Str, *values: Obj) -> Bytes
.pack_into!: (format: Str, buffer: RefMut(ByteArray!), offset: Nat, *values: Obj) => NoneType
.unpack: (format: Str, bytes: Bytes) -> Obj
.unpack_from: (format: Str, buffer: Bytes, offset := Nat) -> [Obj; _]
.iter_unpack: (format: Str, buffer: Bytes) -> Iterator [Obj; _]
.calcsize: (format: Str) -> Nat