### Technical Details: `root_path` { #technical-details-root-path }

When you mount a sub-application as described above, FastAPI will take care of communicating the mount path for the sub-application using a mechanism from the ASGI specification called a `root_path`.

That way, the sub-application will know to use that path prefix for the docs UI.

 * beyond the standard ones provided by Maven (like jar, war, ear, etc.). Implementations of this
 * interface will be discovered through the Java ServiceLoader mechanism and their provided
 * packaging types will be available throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomPackagingProvider implements PackagingProvider {

 * <p>
 * This interface serves as the base for all Service Provider Interface (SPI) components in Maven.
 * Classes implementing this interface can be discovered and loaded by Maven through the
 * Java ServiceLoader mechanism, allowing plugins and extensions to contribute functionality
 * to the Maven build process.
 * <p>
 * SPI services are typically registered in {@code META-INF/services/} files corresponding to

 * of phases that can be executed during a build.
 * <p>
 * Implementations of this interface will be discovered through the Java ServiceLoader mechanism
 * and their provided lifecycles will be available throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomLifecycleProvider implements LifecycleProvider {

 * in different contexts, such as compilation, testing, or runtime.
 * <p>
 * Implementations of this interface will be discovered through the Java ServiceLoader mechanism
 * and their provided path scopes will be available throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomPathScopeProvider implements PathScopeProvider {

 * are handled, including their default extension, classifier, and language.
 * <p>
 * Implementations of this interface will be discovered through the Java ServiceLoader mechanism
 * and their provided types will be available throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomTypeProvider implements TypeProvider {

            // Verify that no renewal happened
            assertFalse(renewed, "renewCredentials should return false if no renewal mechanism succeeds");
            assertEquals(mockCredentials, wrapper.getCredentials(), "Credentials should remain unchanged if no renewal mechanism succeeds");
            // Note: Credentials interface does not have renew() method
        }
    }

 * beyond the standard ones provided by Maven. Implementations of this interface will be discovered
 * through the Java ServiceLoader mechanism and their provided languages will be available
 * throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomLanguageProvider implements LanguageProvider {

 * beyond the standard {@link ProjectScope#MAIN} and {@link ProjectScope#TEST} scopes.
 * Implementations of this interface will be discovered through the Java ServiceLoader mechanism
 * and their provided project scopes will be available throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomProjectScopeProvider implements ProjectScopeProvider {

import java.security.PrivilegedExceptionAction;
import java.util.Random;
import org.jspecify.annotations.Nullable;
import sun.misc.Unsafe;

/**
 * A package-local class holding common representation and mechanics for classes supporting dynamic
 * striping on 64bit values. The class extends Number so that concrete subclasses must publicly do
 * so.
 */
@GwtIncompatible
@SuppressWarnings("SunApi") // b/345822163