"loc": ["query", "token"],
                    "msg": "Field required",
                    "input": None,
                }
            ]
        }
    ) | IsDict(
        # TODO: remove when deprecating Pydantic v1
        {
            "detail": [
                {
                    "loc": ["query", "token"],
                    "msg": "field required",
                    "type": "value_error.missing",

	var field []byte
	_ = field
	var zb0001 uint32
	zb0001, err = dc.ReadMapHeader()
	if err != nil {
		err = msgp.WrapError(err)
		return
	}
	for zb0001 > 0 {
		zb0001--
		field, err = dc.ReadMapKeyPtr()
		if err != nil {
			err = msgp.WrapError(err)
			return
		}
		switch msgp.UnsafeString(field) {
		default:
			err = dc.Skip()
			if err != nil {

	fields := strings.Split(releaseTag, ".")
	if len(fields) < 2 || len(fields) > 4 {
		return releaseTime, fmt.Errorf("%s is not a valid release tag", releaseTag)
	}
	if fields[0] != "RELEASE" {
		return releaseTime, fmt.Errorf("%s is not a valid release tag", releaseTag)
	}
	return time.Parse(MinioReleaseTagTimeLayout, fields[1])
}

            builder.field(SESSION_ID, sessionId);
        }
        if (method != null) {
            builder.field(METHOD, method);
        }
        if (url != null) {
            builder.field(URL, url);
        }
        if (parentUrl != null) {
            builder.field(PARENT_URL, parentUrl);
        }
        if (depth != null) {
            builder.field(DEPTH, depth);
        }

	public static final field INSTANCE Lmockwebserver3/SocketPolicy$DisconnectAtStart;
}

public final class mockwebserver3/SocketPolicy$DisconnectDuringRequestBody : mockwebserver3/SocketPolicy {
	public static final field INSTANCE Lmockwebserver3/SocketPolicy$DisconnectDuringRequestBody;
}

public final class mockwebserver3/SocketPolicy$DisconnectDuringResponseBody : mockwebserver3/SocketPolicy {

        final StringBuilder buf = new StringBuilder(100);
        buf.append(form.q);
        if (!form.fields.isEmpty() && form.fields.containsKey(LABEL_FIELD)) {
            final String[] values = form.fields.get(LABEL_FIELD);
            final List<String> labelList = new ArrayList<>();
            if (values != null) {
                Collections.addAll(labelList, values);

	public static final field DISCONNECT_DURING_RESPONSE_BODY Lokhttp3/mockwebserver/SocketPolicy;
	public static final field DO_NOT_READ_REQUEST_BODY Lokhttp3/mockwebserver/SocketPolicy;
	public static final field EXPECT_CONTINUE Lokhttp3/mockwebserver/SocketPolicy;
	public static final field FAIL_HANDSHAKE Lokhttp3/mockwebserver/SocketPolicy;
	public static final field KEEP_OPEN Lokhttp3/mockwebserver/SocketPolicy;

    }

    @Override
    public Field getField() {
        return field;
    }

    /**
     * プロパティとして認識しているpublicフィールドを設定します。
     *
     * @param field
     *            プロパティとして認識するpublicフィールド
     */
    public void setField(final Field field) {
        this.field = field;
        if (field != null && ModifierUtil.isPublic(field)) {
            readable = true;

    input.addListener(output, rejectionPropagatingExecutor(executor, output));
    return output;
  }

  /*
   * In certain circumstances, this field might theoretically not be visible to an afterDone() call
   * triggered by cancel(). For details, see the comments on the fields of TimeoutFuture.
   */
  @CheckForNull @LazyInit ListenableFuture<? extends I> inputFuture;
  @CheckForNull @LazyInit F function;

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel, Field

app = FastAPI()


class Item(BaseModel):
    name: str = Field(examples=["Foo"])
    description: Union[str, None] = Field(default=None, examples=["A very nice Item"])
    price: float = Field(examples=[35.4])
    tax: Union[float, None] = Field(default=None, examples=[3.2])


@app.put("/items/{item_id}")