</blockquote>

## Investigation

By using all the previous alternatives I had the chance to learn from all of them, take ideas, and combine them in the best way I could find for myself and the teams of developers I have worked with.

For example, it was clear that ideally it should be based on standard Python type hints.

Also, the best approach was to use already existing standards.

# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

name: Can Maven build itself

on: [push, pull_request]

# clear all permissions for GITHUB_TOKEN
permissions: {}

jobs:
  build:

    # execute on any push or pull request from forked repo

  static <E extends @Nullable Object> boolean addAllImpl(
      Multiset<E> self, Collection<? extends E> elements) {
    checkNotNull(self);
    checkNotNull(elements);
    if (elements instanceof Multiset) {
      return addAllImpl(self, cast(elements));
    } else if (elements.isEmpty()) {
      return false;
    } else {
      return Iterators.addAll(self, elements.iterator());
    }
  }

    ImmutableGraph.Builder<N> transitiveClosure =
        GraphBuilder.from(graph).allowsSelfLoops(true).<N>immutable();
    // Every node is, at a minimum, reachable from itself. Since the resulting transitive closure
    // will have no isolated nodes, we can skip adding nodes explicitly and let putEdge() do it.

    if (graph.isDirected()) {

version: '3'

services:
  mysql:
    image: 'mysql/mysql-server:latest'
    ports:
      - "9910:3306"
    environment:
      - MYSQL_DATABASE=gorm
      - MYSQL_USER=gorm
      - MYSQL_PASSWORD=gorm
      - MYSQL_RANDOM_ROOT_PASSWORD="yes"
  postgres:
    image: 'postgres:latest'
    ports:
      - "9920:5432"
    environment:
      - TZ=Asia/Shanghai
      - POSTGRES_DB=gorm
      - POSTGRES_USER=gorm

            // Body and catch blocks of try-catch expressions are used if the try-catch itself
            // is used.
            is KtTryExpression ->
                (parent.tryBlock == child || child in parent.catchClauses) && isUsed(parent)

            // If expressions always use their condition, and the branches are used if the
            // If itself is used as an expression.
            is KtIfExpression ->

then it is a "callable".

## Classes as dependencies

You might notice that to create an instance of a Python class, you use that same syntax.

For example:

```Python
class Cat:
    def __init__(self, name: str):
        self.name = name


fluffy = Cat(name="Mr Fluffy")
```

In this case, `fluffy` is an instance of the class `Cat`.

And to create `fluffy`, you are "calling" `Cat`.

    void setValue(E entry, V value) {
      this.map.entryHelper.setValue(self(), entry, value);
    }

    /** Returns a copy of the given {@code entry}. */
    @CheckForNull
    E copyEntry(E original, E newNext) {
      return this.map.entryHelper.copy(self(), original, newNext);
    }

    AtomicReferenceArray<E> newEntryArray(int size) {

                    checkArgument(elements.length == 1);
                    return Sets.union(Sets.<String>newHashSet(elements), Sets.newHashSet(elements));
                  }
                })
            .named("singleton U itself")
            .withFeatures(CollectionSize.ONE, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {

 */
@Experimental
@Immutable
@SuppressWarnings("checkstyle:InterfaceIsType")
public interface Language extends ExtensibleEnum {

    /**
     * The "none" language. It is not versioned, family is same to itself, and compatible with itself only.
     * In turn, every {@link Language} implementation must be compatible with {@code NONE} language.
     */
    Language NONE = language("none");