{[]string{"", ""}, ""},
		{[]string{"a", "b"}, ""},
		{[]string{"a", "a"}, "a"},
		{[]string{"a/", "a/"}, "a/"},
		{[]string{"abcd/", ""}, ""},
		{[]string{"abcd/foo/", "abcd/bar/"}, "abcd/"},
		{[]string{"abcd/foo/bar/", "abcd/foo/bar/zoo"}, "abcd/foo/bar/"},
	}

	for i, test := range testCases {
		foundPrefix := lcp(test.prefixes, true)
		if foundPrefix != test.commonPrefix {

Then, with a URL like:

```
http://localhost:8000/items/?q=foo&q=bar
```

you would receive the multiple `q` *query parameters'* values (`foo` and `bar`) in a Python `list` inside your *path operation function*, in the *function parameter* `q`.

So, the response to that URL would be:

```JSON
{
  "q": [
    "foo",
    "bar"
  ]
}
```

/// tip

		{getListObjectsV1URL(s.endPoint, bucketName, "", "1000", "url"), []string{"<Key>foo+bar+1</Key>", "<Key>foo+bar+2</Key>", "<Key>foo+%01+bar</Key>"}},
		{
			getListObjectsV2URL(s.endPoint, bucketName, "", "1000", "", "", ""),
			[]string{
				"<Key>foo bar 1</Key>",
				"<Key>foo bar 2</Key>",
				"<Key>foo &#x1; bar</Key>",

		{"210 path=" + longName + "\nabc", "abc", "path", longName, true},
		{"110 path=" + medName + "\n", "", "path", medName, true},
		{"9 foo=ba\n", "", "foo", "ba", true},
		{"11 foo=bar\n\x00", "\x00", "foo", "bar", true},
		{"18 foo=b=\nar=\n==\x00\n", "", "foo", "b=\nar=\n==\x00", true},
		{"27 foo=hello9 foo=ba\nworld\n", "", "foo", "hello9 foo=ba\nworld", true},

{* ../../docs_src/header_params/tutorial003_an_py310.py hl[9] *}

If you communicate with that *path operation* sending two HTTP headers like:

```
X-Token: foo
X-Token: bar
```

The response would be like:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## Recap { #recap }

Declare headers with `Header`, using the same common pattern as `Query`, `Path` and `Cookie`.

This would mean that **FastAPI** would expect a body similar to:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

Again, doing just that declaration, with **FastAPI** you get:

     * @param {number} options.lineDelay - Delay between each line, in ms.
     * @param {number} options.progressLength - Number of characters displayed as progress bar.
     * @param {string} options.progressChar – Character to use for progress bar, defaults to █.
	 * @param {number} options.progressPercent - Max percent of progress.
     * @param {string} options.cursor – Character to use for cursor, defaults to ▋.

We could create an instance of this class with:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

And that way we are able to "parameterize" our dependency, that now has `"bar"` inside of it, as the attribute `checker.fixed_content`.

## Use the instance as a dependency { #use-the-instance-as-a-dependency }

///

#### Data with values for fields with defaults { #data-with-values-for-fields-with-defaults }

But if your data has values for the model's fields with default values, like the item with ID `bar`:

```Python hl_lines="3  5"
{
    "name": "Bar",
    "description": "The bartenders",
    "price": 62,
    "tax": 20.2
}
```

they will be included in the response.

```JSON
{
  "item": "The Foo Wrestlers"
}
```

But if the client requests `http://example.com/items/bar` (a non-existent `item_id` `"bar"`), that client will receive an HTTP status code of 404 (the "not found" error), and a JSON response of:

```JSON
{
  "detail": "Item not found"
}
```

/// tip