sourceMap.put("string", "test");
        sourceMap.put("integer", 42);
        sourceMap.put("long", 100L);
        sourceMap.put("double", 3.14);
        sourceMap.put("boolean", false);
        sourceMap.put("null_value", null);
        sourceMap.put("nested", nestedMap);

        event.setSourceMap(sourceMap);

        Map<String, Object> result = event.toSource();
        assertEquals("test", result.get("string"));

        @Override
        public long process() {
            // This will cause NullPointerException when auto-unboxing
            Long nullValue = null;
            return nullValue;
        }
    }

    // Test class that throws RuntimeException
    private static class RuntimeExceptionScoreBooster extends ScoreBooster {
        @Override

        () -> ImmutableBiMap.ofEntries((Entry<Integer, Integer>) nullKey));
    Entry<Integer, @Nullable Integer> nullValue =
        ImmutableBiMapTest.<@Nullable Integer>entry(23, null);
    assertThrows(
        NullPointerException.class,
        () -> ImmutableBiMap.ofEntries((Entry<Integer, Integer>) nullValue));
  }

  private static <T extends @Nullable Object> Entry<T, T> entry(T key, T value) {

    assertNull(segment.get(new Object(), hash));

    // null key
    DummyEntry<Object, Object> nullEntry = DummyEntry.create(null, hash, entry);
    Object nullValue = new Object();
    ValueReference<Object, Object> nullValueRef = map.newValueReference(nullEntry, nullValue, 1);
    nullEntry.setValueReference(nullValueRef);
    table.set(index, nullEntry);
    // skip the null key
    assertSame(value, segment.get(key, hash));

```

### Type Conversion
```java
import org.codelibs.core.convert.*;

// Safe type conversions with null handling
Integer value = IntegerConversionUtil.toInteger("123");        // Returns 123
Integer nullValue = IntegerConversionUtil.toInteger(null);     // Returns null
Boolean flag = BooleanConversionUtil.toBoolean("true");        // Returns true
Date date = DateConversionUtil.toDate("2023-12-25", "yyyy-MM-dd");

        () -> ImmutableMap.ofEntries((Entry<Integer, Integer>) nullKey));
    Entry<@Nullable Integer, @Nullable Integer> nullValue = entry(23, null);
    assertThrows(
        NullPointerException.class,
        () -> ImmutableMap.ofEntries((Entry<Integer, Integer>) nullValue));
  }

  private static <T> Map<T, T> map(T... keysAndValues) {
    assertThat(keysAndValues.length % 2).isEqualTo(0);