## Use `CORSMiddleware` { #use-corsmiddleware }

You can configure it in your **FastAPI** application using the `CORSMiddleware`.

* Import `CORSMiddleware`.
* Create a list of allowed origins (as strings).
* Add it as a "middleware" to your **FastAPI** application.

You can also specify whether your backend allows:

	// ErrPreloadNotAllowed preload is not allowed when count is used
	ErrPreloadNotAllowed = errors.New("preload is not allowed when count is used")
	// ErrDuplicatedKey occurs when there is a unique key constraint violation
	ErrDuplicatedKey = errors.New("duplicated key not allowed")
	// ErrForeignKeyViolated occurs when there is a foreign key constraint violation

    "--connect-timeout",
  ).help(
    "Maximum time allowed for connection (seconds)",
  ).int()
    .default(DEFAULT_TIMEOUT)

  val readTimeout: Int by option("--read-timeout")
    .help("Maximum time allowed for reading data (seconds)")
    .int()
    .default(DEFAULT_TIMEOUT)

  val callTimeout: Int by option(
    "--call-timeout",
  ).help(
    "Maximum time allowed for the entire call (seconds)",
  ).int()

    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceEntry_unsupportedAbsentKey() {
    try {
      getMap().replace(k3(), v3(), v4());
    } catch (UnsupportedOperationException tolerated) {
      // the operation would be a no-op, so exceptions are allowed but not required
    }
    expectUnchanged();

    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceEntry_unsupportedAbsentKey() {
    try {
      getMap().replace(k3(), v3(), v4());
    } catch (UnsupportedOperationException tolerated) {
      // the operation would be a no-op, so exceptions are allowed but not required
    }
    expectUnchanged();

    }

    /**
     * CORS header for specifying allowed origin.
     */
    protected static final String ACCESS_CONTROL_ALLOW_ORIGIN = "Access-Control-Allow-Origin";

    /**
     * CORS header for specifying allowed headers.
     */
    protected static final String ACCESS_CONTROL_ALLOW_HEADERS = "Access-Control-Allow-Headers";

    /**
     * CORS header for specifying allowed HTTP methods.
     */

    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceEntry_unsupportedAbsentKey() {
    try {
      getMap().replace(k3(), v3(), v4());
    } catch (UnsupportedOperationException tolerated) {
      // the operation would be a no-op, so exceptions are allowed but not required
    }
    expectUnchanged();

    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceEntry_unsupportedAbsentKey() {
    try {
      getMap().replace(k3(), v3(), v4());
    } catch (UnsupportedOperationException tolerated) {
      // the operation would be a no-op, so exceptions are allowed but not required
    }
    expectUnchanged();

// errMethodNotAllowed means that method is not allowed.
var errMethodNotAllowed = errors.New("Method not allowed")

// errSignatureMismatch means signature did not match.
var errSignatureMismatch = errors.New("Signature does not match")

// When upload object size is greater than 5G in a single PUT/POST operation.
var errDataTooLarge = errors.New("Object size larger than allowed limit")

        }
        return true;
    }

    /**
     * Checks if the given value matches any of the specified protocols.
     *
     * @param protocols the allowed protocols
     * @param value the URI string to validate
     * @return true if the value matches allowed protocols, false otherwise
     */
    protected static boolean check(final String[] protocols, final String value) {
        final String[] paths = value.split("[\r\n]");