/**
     * Locates the pom in the given directory.
     *
     * @param dir the directory to locate the pom for, never {@code null}
     * @return a {@code Source} pointing to the located pom or an empty {@code Optional} if none was found by this parser
     */
    @Nonnull
    Optional<Source> locate(@Nonnull Path dir);

    /**
     * Parse the model obtained previously by a previous call to {@link #locate(Path)}.
     *

     * Gets the installation Toolchains source.
     *
     * @return the installation Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getInstallationToolchainsSource();

    /**
     * Gets the user Toolchains source.
     *
     * @return the user Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getUserToolchainsSource();

    @Nonnull

    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

/**
 * @author higa
 */
public class BeanMapTest {

    /**
     * @see org.junit.rules.ExpectedException
     */
    @Rule
    public ExpectedException exception = ExpectedException.none();

    /**
     * @throws Exception
     */
    @Test
    public void testGet() throws Exception {
        final BeanMap map = new BeanMap();
        map.put("aaa", 1);
        map.put("bbb", 2);

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

Использование `Optional[str]` вместо просто `str` позволит редактору помочь вам в обнаружении ошибок, в которых вы могли бы предположить, что значение всегда является `str`, хотя на самом деле это может быть и `None`.

#### Generic-типы

    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

/// tip

👆 💪 🤙 ⚙️ 👉 🎏 ⚒ ⏮️ 🇺🇸🔍 `PUT` 🛠️.

✋️ 🖼 📥 ⚙️ `PATCH` ↩️ ⚫️ ✍ 👫 ⚙️ 💼.

///

/// note

👀 👈 🔢 🏷 ✔.

, 🚥 👆 💚 📨 🍕 ℹ 👈 💪 🚫 🌐 🔢, 👆 💪 ✔️ 🏷 ⏮️ 🌐 🔢 ™ 📦 (⏮️ 🔢 💲 ⚖️ `None`).

🔬 ⚪️➡️ 🏷 ⏮️ 🌐 📦 💲 **ℹ** & 🏷 ⏮️ ✔ 💲 **🏗**, 👆 💪 ⚙️ 💭 🔬 [➕ 🏷](extra-models.md){.internal-link target=_blank}.

    NullPointerTester tester = new NullPointerTester();

    tester.testConstructors(PatternFilenameFilter.class, Visibility.PACKAGE);
    tester.testStaticMethods(PatternFilenameFilter.class, Visibility.PACKAGE); // currently none

    // The reason that we skip this method is discussed in a comment on the method.
    tester.ignore(PatternFilenameFilter.class.getMethod("accept", File.class, String.class));

    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages

    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages