## Optional parameters { #optional-parameters }

The same way, you can declare optional query parameters, by setting their default to `None`:

{* ../../docs_src/query_params/tutorial002_py310.py hl[7] *}

In this case, the function parameter `q` will be optional, and will be `None` by default.

/// check

        )

        # Update a hero
        response = client.patch(
            f"/heroes/{hero_id}", json={"name": "Dog Pond", "age": None}
        )
        assert response.status_code == 200, response.text
        assert response.json() == snapshot(
            {"name": "Dog Pond", "age": None, "id": Is(hero_id)}
        )

        # Get updated hero
        response = client.get(f"/heroes/{hero_id}")

      0xFFFF - 0x0800 + 1 - THREE_BYTE_SURROGATES;

  // 2,650,112
  private static final long EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT =
      // All one byte characters
      (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 3)
          +
          // One two byte character and a one byte character
          2 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS * ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS
          +
          // Three byte characters

 * used. HTTP/1.x connections can carry either zero or one streams. HTTP/2 connections can carry any
 * number of streams, dynamically configured with `SETTINGS_MAX_CONCURRENT_STREAMS`. A connection
 * currently carrying zero streams is an idle stream. We keep it alive because reusing an existing
 * connection is typically faster than establishing a new one.
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

import org.apache.maven.api.services.MavenException;

@Experimental
public class ModelParserException extends MavenException {

    /**
     * The one-based index of the line containing the error.
     */
    private final int lineNumber;

    /**
     * The one-based index of the column containing the error.
     */
    private final int columnNumber;

    public ModelParserException() {
        this(null, null);

        super(
                "Plugin " + plugin.getId() + " or one of its dependencies could not be resolved: " + cause.getMessage(),
                cause);
        this.plugin = plugin;
    }

    public PluginResolutionException(Plugin plugin, List<Exception> exceptions, Throwable cause) {
        super(
                "Plugin " + plugin.getId() + " or one of its dependencies could not be resolved:"

     * @param begin the timestamp when tracking began
     * @param done whether tracking was completed normally
     */
    protected void printStats(final Object keyObj, final StatsObject data, final long begin, final boolean done) {
        final StringBuilder buf = createStringBuffer(keyObj, begin);
        if (done) {
            buf.append('\t').append("done:").append(getCurrentTimeMillis() - begin);
        }
        data.entrySet()

     *
     * - If the stack overflowed after set()/setValue() stored its result, then a call to
     * setException() will be a no-op because the Future is already done.
     *
     * Both scenarios are bad: The output Future might never complete, or, if it does complete, it
     * might not run some of its listeners. The likely result is that the app will hang. (And of

        sb.append("      id: ").append(getId()).append(LS);
        sb.append("      url: ").append(getUrl()).append(LS);
        sb.append("   layout: ").append(layout != null ? layout : "none");

        if (proxy != null) {
            sb.append(LS)
                    .append("    proxy: ")
                    .append(proxy.getHost())
                    .append(':')