| n | from typing import List, TypeVar, MutableSequence | n | from typing import List, TypeVar, MutableSequence, cast | 
            |  | T = TypeVar('T', int, float, str, List[str]) |  | T = TypeVar('T', int, float, str, List[str]) | 
            |  | Sortable = MutableSequence[T] |  | Sortable = MutableSequence[T] | 
            |  |  |  |  | 
            | t | def bubble(seq: Sortable) -> Sortable: | t | def bubble(sequence: Sortable) -> Sortable: | 
            |  | n = len(seq) |  | length = len(sequence) | 
            |  | for i in range(n): |  | for i in range(length): | 
            |  | for j in range(0, n - i - 1): |  | for j in range(0, length - i - 1): | 
            |  | if seq[j] > seq[j + 1]: |  | if sequence[j] > sequence[j + 1]: | 
            |  | seq[j], seq[j + 1] = (seq[j + 1], seq[j]) |  | sequence[j], sequence[j + 1] = (sequence[j + 1], sequence[j]) | 
            |  | return seq |  | return sequence |