} else {
      assertThrows(UnsupportedOperationException.class, () -> map.clear());
    }
    assertInvariants(map);
  }

  @J2ktIncompatible // https://youtrack.jetbrains.com/issue/KT-58242/ undefined behavior (crash)
  public void testContainsKey() {
    Map<K, V> map;
    K unmappedKey;
    try {
      map = makePopulatedMap();
      unmappedKey = getKeyNotInPopulatedMap();

 * multimap is modified while an iteration over any of those collections is in progress, except
 * through the iterator's methods, the results of the iteration are undefined.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *

### Short

It has sensible **defaults** for everything, with optional configurations everywhere. All the parameters can be fine-tuned to do what you need and to define the API you need.

But by default, it all **"just works"**.

### Validation

* Validation for most (or all?) Python **data types**, including:
    * JSON objects (`dict`).

    // vol. 2, Knuth, 4.2.2, (16) to the two-variable case. We have two value series x_i and y_i.
    // We define the arithmetic means X_n = 1/n \sum_{i=1}^n x_i, and Y_n = 1/n \sum_{i=1}^n y_i.
    // We also define the sum of the products of the differences from the means
    //           C_n = \sum_{i=1}^n x_i y_i - n X_n Y_n
    // for all n >= 1. Then for all n > 1:

```
KEY:
storage_class  define object level redundancy

ARGS:
standard  (string)    set the parity count for default standard storage class e.g. "EC:4"
rrs       (string)    set the parity count for reduced redundancy storage class e.g. "EC:2"
comment   (sentence)  optionally add a comment to this setting
```

or environment variables

```
KEY:
storage_class  define object level redundancy

ARGS:

# libraries are language agnostic.
#
# This shared object is not used unless framework_shared_object=true (set in the
# configure script unconditionally); otherwise if it is false or undefined, the
# build is static and TensorFlow symbols (in Python only) are loaded into the
# global symbol table in order to support op registration. This means that

      assertTaskWrapped(tasks);
      lastMethodCalled = "invokeAllTimeout";
      lastTimeoutInMillis = unit.toMillis(timeout);
      return inline.invokeAll(tasks, timeout, unit);
    }

    // Define the invokeAny methods to invoke the first task
    @Override
    public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
        throws ExecutionException, InterruptedException {
      assertTaskWrapped(tasks);

    <suppress checks="JavadocPackage"
              files=".*[/\\]platforms[/\\]ide[/\\]ide-plugins[/\\]src[/\\]main[/\\]java[/\\]org[/\\]gradle[/\\]plugins[/\\]ide[/\\]eclipse[/\\][^/\\]+"/>

    <!-- Protocol types may only define constants in interfaces -->
    <suppress checks="InterfaceIsTypeCheck"
              files=".*[/\\]tooling-api[/\\]src[/\\]main[/\\]java[/\\]org[/\\]gradle[/\\]tooling[/\\]internal[/\\]protocol.+"/>

TRANSITION_END,\n    delegateType: TRANSITION_END,\n    handle(event) {\n      if ($(event.target).is(this)) {\n        return event.handleObj.handler.apply(this, arguments) // eslint-disable-line prefer-rest-params\n      }\n      return undefined // eslint-disable-line no-undefined\n    }\n  }\n}\n\nfunction transitionEndEmulator(duration) {\n  let called = false\n\n  $(this).one(Util.TRANSITION_END, () => {\n    called = true\n  })\n\n  setTimeout(() => {\n    if (!called) {\n      Util.triggerTransitionEnd(this)\n...

///

Here we define the config `env_file` inside of your Pydantic `Settings` class, and set the value to the filename with the dotenv file we want to use.

### Creating the `Settings` only once with `lru_cache`