//Installation and Upgrade Guide
<% if (breakingChangesByNotabilityByArea.isEmpty() == false) { %>
[discrete]
[[breaking-changes-${majorDotMinor}]]
=== Breaking changes

The following changes in {es} ${majorDotMinor} might affect your applications
and prevent them from operating normally.
Before upgrading to ${majorDotMinor} review these changes and take the described steps
to mitigate the impact.

        .addEqualityGroup(
            newDelegatingListWithEquals(LIST2),
            newProxyWithSubHandler1(LIST2), // Makes sure type of handler doesn't affect equality
            newProxyWithSubHandler2(LIST2))
        .addEqualityGroup(newDelegatingIterableWithEquals(LIST2)) // different interface
        .testEquals();
  }

            log.error("Failed to reset SingletonContext instance", e);
            fail("Failed to reset SingletonContext instance: " + e.getMessage());
        }
        // Clear system properties that might affect the test
        System.clearProperty("jcifs.properties");
        System.clearProperty("java.protocol.handler.pkgs");
        // Clear jcifs-specific properties to prevent test interference

I think `Union[SomeType, None]` is more explicit about what it means.

It's just about the words and names. But those words can affect how you and your teammates think about the code.

As an example, let's take this function:

```python
from typing import Optional


def say_hi(name: Optional[str]):
    print(f"Hey {name}!")
```

    /**
     * Invoked after MavenSession instance has been created.
     *
     * This callback is intended to allow extensions to inject execution properties,
     * activate profiles and perform similar tasks that affect MavenProject
     * instance construction.
     *
     * @param session the Maven session
     * @throws MavenExecutionException in case of issue
     */

    /**
     * upperBoundWindow represents the headMap/subMap/tailMap view of the entire "ranges by upper
     * bound" map; it's a constraint on the *keys*, and does not affect the values.
     */
    private final Range<Cut<C>> upperBoundWindow;

    RangesByUpperBound(NavigableMap<Cut<C>, Range<C>> rangesByLowerBound) {
      this.rangesByLowerBound = rangesByLowerBound;

import java.util.Set;

/**
 * Result of an upgrade strategy application.
 * Uses sets of paths to track which POMs were processed, modified, or had errors,
 * avoiding double-counting when multiple strategies affect the same POMs.
 *
 * @param processedPoms the set of POMs that were processed
 * @param modifiedPoms the set of POMs that were modified
 * @param errorPoms the set of POMs that had errors
 */

        CharMappingItem item = new CharMappingItem(1L, originalInputs, "output");

        String[] returnedInputs = item.getInputs();

        // Modifying returned array should not affect original
        returnedInputs[0] = "modified";

        // Get again and verify not modified
        String[] inputs2 = item.getInputs();
        assertEquals("a", inputs2[0]);

   * unprivileged user may return a resource accessible only to a privileged user making a similar
   * call. To prevent this problem, create a key object that includes all values that affect the
   * result of the query. Or use {@code LoadingCache.get(K)}, which lacks the ability to refer to
   * state other than that in the key.
   *

        return params.containsKey(key);
    }

    /**
     * Returns a copy of the internal parameter map as a standard Map.
     * The returned map is a copy and modifications will not affect this instance.
     *
     * @return a new Map containing all current parameters
     */
    public Map<String, Object> asMap() {
        return new ParamMap<>(new HashMap<>(getDataMap(params)));
    }