### Est-ce que la concurrence est mieux que le parallélisme ?

Nope ! C'est ça la morale de l'histoire.

### Internal

* ♻ Refactor dict value extraction to minimize key lookups `fastapi/utils.py`. PR [#3139](https://github.com/tiangolo/fastapi/pull/3139) by [@ShahriyarR](https://github.com/ShahriyarR).
* ✅ Add tests for required nonable parameters and body fields. PR [#4907](https://github.com/tiangolo/fastapi/pull/4907) by [@tiangolo](https://github.com/tiangolo).

    def is_scalar_sequence_field(field: ModelField) -> bool:
        return field_annotation_is_scalar_sequence(field.field_info.annotation)

    def is_bytes_field(field: ModelField) -> bool:
        return is_bytes_or_nonable_bytes_annotation(field.type_)

    def is_bytes_sequence_field(field: ModelField) -> bool:
        return is_bytes_sequence_annotation(field.type_)

    get_annotation_from_field_info,
    get_missing_field_error,
    is_bytes_field,
    is_bytes_sequence_field,
    is_scalar_field,
    is_scalar_sequence_field,
    is_sequence_field,
    is_uploadfile_or_nonable_uploadfile_annotation,
    is_uploadfile_sequence_annotation,
    lenient_issubclass,
    sequence_types,
    serialize_sequence_value,
    value_is_sequence,
)
from fastapi.background import BackgroundTasks