## Parameterize the instance

And now, we can use `__init__` to declare the parameters of the instance that we can use to "parameterize" the dependency:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[9] *}

In this case, **FastAPI** won't ever touch or care about `__init__`, we will use it directly in our code.

## Create an instance

We could create an instance of this class with:

        try {
            Class<?> clazz = container.getContainerRealm().loadClass(PROMPTER_CLASS);
            Object instance = container.lookup(clazz);
            Method method = clazz.getMethod("prompt", String.class, List.class, String.class);
            return (String) method.invoke(instance, message, possibleValues, defaultReply);
        } catch (Exception e) {
            throw new PrompterException("Unable to call prompter", e);

    instance := grid.NewStream[*Payload, *Req, *Resp](h, newPayload, newReq, newResp)
	
    // Tweakable options
    instance.WithPayload = true // default true when newPayload != nil
    instance.OutCapacity = 1    // default
    instance.InCapacity = 1     // default true when newReq != nil
	
    // Register the handler on the manager
    instance.Register(manager, handler, "asubroute")
	

          .put(ImmutableClassToInstanceMap.class, ImmutableClassToInstanceMap.builder().build())
          .put(Comparable.class, ByToString.INSTANCE)
          .put(Comparator.class, AlwaysEqual.INSTANCE)
          .put(Ordering.class, AlwaysEqual.INSTANCE)
          .put(Range.class, Range.all())
          .put(MapDifference.class, Maps.difference(ImmutableMap.of(), ImmutableMap.of()))
          .put(

        return singleton(name, instance, initializer, null);
    }

    public <T> StandardCrawlerContainer singleton(final String name, final T instance) {
        return singleton(name, instance, null, null);
    }

    protected static class ComponentHolder<T> {
        protected T instance;

        protected Consumer<T> destroyer;

		Long:  `Retrieve information about certificates for the Ztunnel instance.`,
		Example: `  # Retrieve summary about workload configuration for a randomly chosen ztunnel.
  istioctl ztunnel-config certificates

  # Retrieve full certificate dump of workloads for a given Ztunnel instance.
  istioctl ztunnel-config certificates <ztunnel-name[.namespace]> -o json
`,

  public void testToString() {
    assertEquals("{}", INSTANCE.toString());
  }

  public void testSize() {
    assertEquals(0, INSTANCE.size());
  }

  public void testGet() {
    assertNull(INSTANCE.get('a', 1));
  }

  public void testIsEmpty() {
    assertTrue(INSTANCE.isEmpty());
  }

  public void testCellSet() {
    assertEquals(ImmutableSet.of(), INSTANCE.cellSet());
  }

  public void testColumn() {

        "alertname": "MinIOClusterTolerance",
        "instance": "localhost:9000",
        "job": "minio-job-node",
        "pool": "0",
        "server": "127.0.0.1:9000",
        "set": "0",
        "severity": "critical"
      },
      "annotations": {
        "description": "MinIO instance 127.0.0.1:9000 of job minio-job has tolerance <=0 for more than 5 minutes.",
        "summary": "Instance 127.0.0.1:9000 unable to tolerate node failures"

  }

  Optional() {}

  /**
   * Returns {@code true} if this holder contains a (non-null) instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> no differences.
   */
  public abstract boolean isPresent();

  /**
   * Returns the contained instance, which must be present. If the instance might be absent, use
   * {@link #or(Object)} or {@link #orNull} instead.
   *

        } catch (final Exception e) {
            throw new IllegalArgumentException("Cannot create instance of: " + clazz, e);
        } catch (final LinkageError e) {
            throw new IllegalArgumentException("Cannot create instance of: " + clazz, e);
        }
    }

    /**
     * Creates an instance of the given implementation using the given string, assumes a public string constructor.
     *