# Header Parameter Models

If you have a group of related **header parameters**, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Header Parameters with a Pydantic Model

                            },
                            "name": "item_id",
                            "in": "path",
                        },
                        {
                            "required": False,
                            "schema": IsDict(
                                {
                                    "anyOf": [{"type": "string"}, {"type": "null"}],
                                    "title": "Q",

            throwValidationErrorApi(messages -> messages.addErrorsCrudCouldNotFindCrudTable(GLOBAL, body.id));
            return null;
        });
        return asJson(new ApiUpdateResponse().id(relatedQuery.getId()).created(false).status(Status.OK).result());
    }

    // DELETE /api/admin/relatedquery/setting/{id}
    @Execute
    public JsonResponse<ApiResult> delete$setting(final String id) {

                                                test="${available=='true'}">
                                            <la:message key="labels.enabled"/>
                                        </c:if> <c:if test="${available=='false'}">
                                            <la:message key="labels.disabled"/>
                                        </c:if></td>
                                    </tr>
                                    <tr>

  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_unsupportedPresent() {
    try {
      assertFalse("add(present) should return false or throw", collection.add(e0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @CollectionFeature.Require(
      value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES},

import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A mutable type-to-instance map. See also {@link ImmutableTypeToInstanceMap}.
 *
 * @author Ben Yu
 * @since 13.0
 */
@ElementTypesAreNonnullByDefault
public final class MutableTypeToInstanceMap<B extends @Nullable Object>

  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_unsupportedPresent() {
    try {
      assertFalse("add(present) should return false or throw", collection.add(e0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @CollectionFeature.Require(
      value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES},

    }
    if (args.length == 1
        && method.getName().equals("equals")
        && method.getParameterTypes()[0] == Object.class) {
      Object arg = args[0];
      if (arg == null) {
        return false;
      }
      if (proxy == arg) {
        return true;
      }
      return isProxyOfSameInterfaces(arg, proxy.getClass())
          && equals(Proxy.getInvocationHandler(arg));
    }

 * {@link ValueGraph}, and {@link Network}):
 *
 * <pre>{@code
 * someGraphAlgorithm(startNode, graph);
 * }</pre>
 *
 * This works because those types each implement {@code SuccessorsFunction}. It will also work with
 * any other implementation of this interface.
 *
 * <p>If you have your own graph implementation based around a custom node type {@code MyNode},

        return exception;
    }

    @Override
    public String getMessage() {
        String msg = null;

        if (message != null && !message.isEmpty()) {
            msg = message;
        } else if (exception != null) {
            msg = exception.getMessage();
        }

        if (msg == null) {
            msg = "";
        }

        return msg;
    }

    @Override