if (node.previousSibling == null) {
        // requireNonNull is safe because we checked that not *both* siblings were null.
        keyList.head = requireNonNull(node.nextSibling);
      } else {
        node.previousSibling.nextSibling = node.nextSibling;
      }

      if (node.nextSibling == null) {
        // requireNonNull is safe because we checked that not *both* siblings were null.

For the error, we use the exception `HTTPException`:

{* ../../docs_src/security/tutorial003_an_py310.py hl[3,79:81] *}

### Check the password { #check-the-password }

At this point we have the user data from our database, but we haven't checked the password.

Let's put that data in the Pydantic `UserInDB` model first.

	pp.SetContentType("image/jpeg")
	pp.SetUserMetadata("uuid", "14365123651274")
	pp.SetKeyStartsWith("user/user1/filename")
	pp.SetContentLengthRange(100, 999999) // not testable from this layer, condition is checked in the API handler.
	pp.SetSuccessStatusAction("201")
	pp.SetCondition("eq", "X-Amz-Credential", "KVGKMDUQ23TCZXTLTHLP/20160727/us-east-1/s3/aws4_request")
	pp.SetCondition("eq", "X-Amz-Algorithm", "AWS4-HMAC-SHA256")

}

// checkPostPolicy - apply policy conditions and validate input values.
// Note that content-length-range is checked in the API handler function PostPolicyBucketHandler.
// formValues is the already-canonicalized form values from the POST request.
func checkPostPolicy(formValues http.Header, postPolicyForm PostPolicyForm) error {
	// Check if policy document expiry date is still not reached
	if !postPolicyForm.Expiration.After(UTCNow()) {

  }

  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  protected final boolean supportsValuesHashCode(Map<K, V> map) {
    // get the first non-null value
    Collection<V> values = map.values();
    for (V value : values) {
      if (value != null) {
        try {
          int unused = value.hashCode();
        } catch (Exception e) { // sneaky checked exception
          return false;
        }

   * true when removing a connection from the pool; otherwise a racing caller might get it from the
   * pool when it shouldn't. Symmetrically, this must always be checked before returning a
   * connection from the pool.
   *
   * Once true this is always true. Guarded by this.
   */
  var noNewExchanges = false

  /**

    * Use of hierarchical Pydantic models, Python `typing`’s `List` and `Dict`, etc.
    * And validators allow complex data schemas to be clearly and easily defined, checked and documented as JSON Schema.
    * You can have deeply **nested JSON** objects and have them all validated and annotated.
* **Extensible**:

     * <p><b>Note:</b> in general, code should assume that the string form returned by {@code
     * ToStringHelper} for a given object may change. In particular, the list of types which are
     * checked for emptiness is subject to change. We currently check {@code CharSequence}s, {@code
     * Collection}s, {@code Map}s, optionals (including Guava's), and arrays.
     *
     * @since 33.4.0
     */
    @CanIgnoreReturnValue

		return nil
	})
}

// listPath will return the requested entries.
// If no more entries are in the listing io.EOF is returned,
// otherwise nil or an unexpected error is returned.
// The listPathOptions given will be checked and modified internally.
// Required important fields are Bucket, Prefix, Separator.
// Other important fields are Limit, Marker.
// List ID always derived from the Marker.

  /**
   * A boolean condition for which a thread may wait. A {@code Guard} is associated with a single
   * {@code Monitor}. The monitor may check the guard at arbitrary times from any thread occupying
   * the monitor, so code should not be written to rely on how often a guard might or might not be
   * checked.
   *
   * <p>If a {@code Guard} is passed into any method of a {@code Monitor} other than the one it is