{* ../../docs_src/python_types/tutorial005_py39.py hl[1] *}

### Generic types with type parameters { #generic-types-with-type-parameters }

There are some data structures that can contain other values, like `dict`, `list`, `set` and `tuple`. And the internal values can have their own type too.

These types that have internal types are called "**generic**" types. And it's possible to declare them, even with their internal types.

	http.Header
}

func newFormValues() formValues {
	return formValues{make(http.Header)}
}

func (f formValues) Set(key, value string) formValues {
	f.Header.Set(key, value)
	return f
}

func (f formValues) Add(key, value string) formValues {
	f.Header.Add(key, value)
	return f
}

func (f formValues) Clone() formValues {
	return formValues{f.Header.Clone()}
}

 *       as that of its keys. This is sometimes called an "invertible map," since the restriction on
 *       values enables it to support an {@linkplain BiMap#inverse inverse view} -- which is another
 *       instance of {@code BiMap}.
 *   <dt>{@link Table}
 *   <dd>A new type, which is similar to {@link java.util.Map}, but which indexes its values by an

            continue
        if isinstance(value, dict):
            new_schema[key] = _replace_refs(
                schema=value,
                old_name_to_new_name_map=old_name_to_new_name_map,
            )
        elif isinstance(value, list):
            new_value = []
            for item in value:
                if isinstance(item, dict):
                    new_item = _replace_refs(

pkg os, func CopyFS(string, fs.FS) error #62484
pkg path/filepath, func Localize(string) (string, error) #57151
pkg reflect, func SliceAt(Type, unsafe.Pointer, int) Value #61308
pkg reflect, method (Value) Seq() iter.Seq[Value] #66056
pkg reflect, method (Value) Seq2() iter.Seq2[Value, Value] #66056
pkg reflect, type Type interface, CanSeq() bool #66056
pkg reflect, type Type interface, CanSeq2() bool #66056

      Class<@NonNull T> type, @ParametricNullness T value) {
    return trustedPut(TypeToken.of(type), value);
  }

  @Override
  @CanIgnoreReturnValue
  public <T extends B> @Nullable T putInstance(
      TypeToken<@NonNull T> type, @ParametricNullness T value) {
    return this.<T>trustedPut(type.rejectTypeVariables(), value);
  }

  /**
   * Not supported. Use {@link #putInstance} instead.
   *

	}

	// Since the list of signed headers value contained `expect`, the default value of `100-continue` will be added to extracted signed headers.
	if extractedExpect != expectedExpect {
		t.Errorf("expect header incorrect value: expected `%s`, got `%s`", expectedExpect, extractedExpect)
	}

     */
    @Nonnull
    Optional<List<String>> goals();

    /**
     * Returns the target POM model version for upgrades.
     * Supported values include "4.0.0" and "4.1.0".
     *
     * @return an {@link Optional} containing the model version, or empty if not specified
     */
    @Nonnull
    Optional<String> modelVersion();

    /**

Then you can write a template at `templates/item.html` with, for example:

```jinja hl_lines="7"
{!../../docs_src/templates/templates/item.html!}
```

### Template Context Values { #template-context-values }

In the HTML that contains:

{% raw %}

```jinja
Item ID: {{ id }}
```

{% endraw %}

...it will show the `id` taken from the "context" `dict` you passed:

```Python

in an unspecified order.
This means that races on multiword data structures
can lead to inconsistent values not corresponding to a single write.
When the values depend on the consistency
of internal (pointer, length) or (pointer, type) pairs,
as can be the case for interface values, maps,
slices, and strings in most Go implementations,
such races can in turn lead to arbitrary memory corruption.
</p>

<p>