period. The last release to remove non-`@Beta` APIs was Guava 21.0.) Even
    `@Deprecated` APIs will remain (again, unless they are `@Beta`). We have no
    plans to start removing things again, but officially, we're leaving our
    options open in case of surprises (like, say, a serious security problem).

3.  Guava has one dependency that is needed for linkage at runtime:

So, in our example, we can make `tags` be specifically a "list of strings":

{* ../../docs_src/body_nested_models/tutorial002_py310.py hl[12] *}

## Set types { #set-types }

But then we think about it, and realize that tags shouldn't repeat, they would probably be unique strings.

And Python has a special data type for sets of unique items, the `set`.

Then we can declare `tags` as a set of strings:

import org.apache.maven.project.MavenProject;

/**
 * Wraps an active project instance to be able to receive updates from its artifact without affecting the original
 * attributes of this artifact.
 *
 * TODO I think this exposes a design flaw in that the immutable and mutable parts of an artifact are in one class and
 * should be split. ie scope, file, etc depend on the context of use, whereas everything else is immutable.
 */
@Deprecated

  public static void startFinalizer(
      Class<?> finalizableReferenceClass,
      ReferenceQueue<Object> queue,
      PhantomReference<Object> frqReference) {
    /*
     * We use FinalizableReference.class for two things:
     *
     * 1) To invoke FinalizableReference.finalizeReferent()
     *
     * 2) To detect when FinalizableReference's class loader has to be garbage collected, at which
     * point, Finalizer can stop running

 maven.home            (system,user,default=${user.home}/m2)
 maven.repo.local      (system,user,default=${maven.user.config.dir}/repository)

 We need to define what happens in the when things are not setup correctly

 o ~/.m2 directory does not exist
 o ~/.m2/maven.properties does not exist
 o if they once existed but now to do not exist

      boolean isPossibleChainingCall = interfaceType.isAssignableFrom(method.getReturnType());
      try {
        Object actualReturnValue = method.invoke(wrapper, passedArgs);
        // If we think this might be a 'chaining' call then we allow the return value to either
        // be the wrapper or the returnValue.
        if (!isPossibleChainingCall || wrapper != actualReturnValue) {
          assertEquals(

    /*
     * pred and succ are nullable after construction, but we always call successor() to initialize
     * them immediately thereafter.
     *
     * They may be subsequently nulled out by TreeMultiset.clear(). I think that the only place that
     * we can reference a node whose fields have been cleared is inside the iterator (and presumably
     * only under concurrent modification).
     *

      .build()
    assertThat(original.interceptors.size).isEqualTo(0)
    assertThat(original.networkInterceptors.size).isEqualTo(0)
  }

  /**
   * When copying the client, stateful things like the connection pool are shared across all
   * clients.
   */
  @Test fun cloneSharesStatefulInstances() {
    val client = clientTestRule.newClient()

    // Values should be non-null.

    /*
     * pred and succ are nullable after construction, but we always call successor() to initialize
     * them immediately thereafter.
     *
     * They may be subsequently nulled out by TreeMultiset.clear(). I think that the only place that
     * we can reference a node whose fields have been cleared is inside the iterator (and presumably
     * only under concurrent modification).
     *

  `Headers.of(String...)` with `headersOf(vararg String)`.

#### Extension Functions

We’ve migrated from static functions to extension functions where we think they fit.

| Java                                | Kotlin                          |
| :---------------------------------- | :------------------------------ |