Shinsuke Sugaya <******@****.***> 1514783567 +0900

named `/godebug/non-default-behavior/<name>:events`
that counts the number of times a particular program's
behavior has changed based on a non-default value
for that setting.
For example, when `GODEBUG=http2client=0` is set,
`/godebug/non-default-behavior/http2client:events`
counts the number of HTTP transports that the program
has configured without HTTP/2 support.

## Default GODEBUG Values {#default}

Your response model could have default values, like:

{* ../../docs_src/response_model/tutorial004_py310.py hl[9,11:12] *}

* `description: Union[str, None] = None` (or `str | None = None` in Python 3.10) has a default of `None`.
* `tax: float = 10.5` has a default of `10.5`.
* `tags: List[str] = []` has a default of an empty list: `[]`.

  <p>This is a reference for the Core Extensions descriptor.</p>
  <p>The default location for the Core Extensions descriptor file is <code>${maven.projectBasedir}/.mvn/extensions.xml</code></p>
  ]]></description>

  <defaults>
    <default>
      <key>package</key>
      <value>org.apache.maven.cli.internal.extension.model</value>
    </default>
  </defaults>

  <classes>

     *
     * @return timeout for establishing a socket connection, in milliseconds
     */
    int getConnTimeout();

    /**
     * Property {@code jcifs.smb.client.sessionTimeout} (int, default 35000)
     *
     *
     * @return timeout for SMB sessions, in milliseconds
     */
    int getSessionTimeout();

    /**
     *

        // Test default values
        assertFalse(config.isUseRDMA(), "RDMA should be disabled by default");
        assertEquals("auto", config.getRdmaProvider(), "Default provider should be auto");
        assertEquals(8192, config.getRdmaReadWriteThreshold(), "Default threshold should be 8KB");
        assertEquals(65536, config.getRdmaMaxSendSize(), "Default max send size should be 64KB");

        assertEquals(4, config.getMaxChannels(), "Default max channels should be 4");
        assertEquals(1, config.getChannelBindingPolicy(), "Default binding policy should be preferred");
        assertEquals("adaptive", config.getLoadBalancingStrategy(), "Default strategy should be adaptive");
        assertEquals(10, config.getChannelHealthCheckInterval(), "Default health check interval should be 10");
    }

    @Nonnull
    Toolchain createToolchain(@Nonnull ToolchainModel model) throws ToolchainFactoryException;

    /**
     * Creates a default toolchain instance using system defaults.
     *
     * @return Optional containing the default toolchain if available
     * @throws ToolchainFactoryException if default toolchain creation fails
     */
    @Nonnull
    Optional<Toolchain> createDefaultToolchain() throws ToolchainFactoryException;

    This is the model specification for <code>${basedir}/profiles.xml</code>.
  ]]></description>
  <defaults>
    <default>
      <key>package</key>
      <value>org.apache.maven.profiles</value>
    </default>
  </defaults>
  <classes>
    <class rootElement="true" xml.tagName="profilesXml">
      <name>ProfilesRoot</name>
      <version>1.0.0</version>

    /**
     * Specifies the default value of the configuration property.
     *
     * @return the default value as a string, defaults to empty string
     */
    String defaultValue() default "";

    /**
     * Specifies whether the configuration property is read-only.
     *
     * @return true if the property is read-only, false otherwise
     */
    boolean readOnly() default false;

    /**