```

## Using the same dependency multiple times { #using-the-same-dependency-multiple-times }

If one of your dependencies is declared multiple times for the same *path operation*, for example, multiple dependencies have a common sub-dependency, **FastAPI** will know to call that sub-dependency only once per request.

   * documentation for {@link Collection}:
   *
   * <blockquote>
   *
   * "Some collection implementations have restrictions on the elements that they may contain. For
   * example, some implementations prohibit null elements, and some have restrictions on the types
   * of their elements."
   *
   * </blockquote>
   */
  RESTRICTS_ELEMENTS,

  /**

 *
 * <p>This class uses a specified Transliterator to perform text normalization.
 * The Transliterator is initialized with a given ID during the construction of
 * the ICUNormalizer instance.</p>
 *
 * <p>Example usage:</p>
 * <pre>
 * ICUNormalizer normalizer = new ICUNormalizer("Any-Latin; NFD; [:Nonspacing Mark:] Remove; NFC");
 * String normalizedText = normalizer.normalize("text to normalize", "field");
 * </pre>
 *

     *
     * @return the (case-sensitive) identifier, never {@code null}
     */
    @Nonnull
    String getId();

    /**
     * Gets the type of the repository, for example "default".
     *
     * @return the (case-sensitive) type of the repository, never {@code null}
     */
    @Nonnull
    String getType();

				"application/edi-consent",
				"application/edi-x12",
				"application/edifact",
				"application/emma+xml",
				"application/epp+xml",
				"application/epub+zip",
				"application/eshop",
				"application/example",
				"application/fastinfoset",
				"application/fastsoap",
				"application/fits",
				"application/font-tdpfr",
				"application/h224",
				"application/http",
				"application/hyperstudio",

 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingDeque} forward <b>indiscriminately</b> to the
 * methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change the
 * behavior of {@link #offer} which can lead to unexpected behavior. In this case, you should
 * override {@code offer} as well.
 *

     * creator of the problem, the general expectation is that the hint provides sufficient information to the user to
     * track the problem back to its origin. A concrete example for such a source hint can be the file path or URL from
     * which the settings were read.
     *
     * @return The hint about the source of the problem or an empty string if unknown, never {@code null}.
     */

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package provider

import "errors"

// DiscoveryDoc - parses the output from openid-configuration
// for example https://accounts.google.com/.well-known/openid-configuration
//
//nolint:unused
type DiscoveryDoc struct {
	Issuer                           string   `json:"issuer,omitempty"`

You can define those cases using a list in the type declaration.

You will receive all the values from the duplicate header as a Python `list`.

For example, to declare a header of `X-Token` that can appear more than once, you can write:

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

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

You will learn more about adding extra information later in the docs, when learning to declare examples.

/// warning

Extra keys passed to `Field` will also be present in the resulting OpenAPI schema for your application.
As these keys may not necessarily be part of the OpenAPI specification, some OpenAPI tools, for example [the OpenAPI validator](https://validator.swagger.io/), may not work with your generated schema.

///