where an integer (but not int typed) is used. Encoding this as a float
    results in failed round-tripping between encode and parse.
    Our Id type is a prime example of this.

    >>> decimal_encoder(Decimal("1.0"))
    1.0

    >>> decimal_encoder(Decimal("1"))
    1

    >>> decimal_encoder(Decimal("NaN"))
    nan
    """
    exponent = dec_value.as_tuple().exponent
    if isinstance(exponent, int) and exponent >= 0:

### Refactors

* ♻️ Refactor internal `check_file_field()`, rename to `ensure_multipart_is_installed()` to clarify its purpose. PR [#12106](https://github.com/fastapi/fastapi/pull/12106) by [@tiangolo](https://github.com/tiangolo).