## 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);

          .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
`,

  }

  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.
     *

r=le({},p,l[n])}return e}},offset:{order:200,enabled:!0,fn:J,offset:0},preventOverflow:{order:300,enabled:!0,fn:function(e,t){var o=t.boundariesElement||p(e.instance.popper);e.instance.reference===o&&(o=p(o));var n=B('transform'),i=e.instance.popper.style,r=i.top,s=i.left,d=i[n];i.top='',i.left='',i[n]='';var a=v(e.instance.popper,e.instance.reference,t.padding,o,e.positionFixed);i.top=r,i.left=s,i[n]=d,t.boundaries=a;var l=t.priority,f=e.offsets.popper,m={primary:function(e){var o=f[e];return f...

    }

    /**
     * Serialize the inbound Model instance to a StringWriter, perform the regex replacement to resolve
     * POM expressions, then re-parse into the resolved Model instance.
     * <p>
     * <b>NOTE:</b> This will result in a different instance of Model being returned!!!
     *
     * @param model The inbound Model instance, to serialize and reference for expression resolution

			impersonateGroup: nil,
			namespace:        ptr.Of[string](""),
			istioNamespace:   ptr.Of[string](""),
			defaultNamespace: "",
		}
	}
	return &instance{
		RootFlags: *rootFlags,
	}
}

func (i *instance) getImpersonateConfig() rest.ImpersonationConfig {
	impersonateConfig := rest.ImpersonationConfig{}
	if len(*i.impersonate) > 0 {
		impersonateConfig.UserName = *i.impersonate