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

// Primitive conversions with default values
int primitiveInt = IntegerConversionUtil.toPrimitiveInt(value, "0");  // Default to 0 if null
```

### Collection Utilities with Java 21 Support
```java

	for i := start; i <= number; i++ {
		if paddinglen == 0 {
			seq = append(seq, fmt.Sprintf("%d", i))
		} else {
			seq = append(seq, fmt.Sprintf(fmt.Sprintf("%%0%dd", paddinglen), i))
		}
	}
	return seq
}

// Test tests parses endpoint ellipses input pattern.
func TestParseEndpointSet(t *testing.T) {
	testCases := []struct {
		arg     string

	var err error
	if fi.VersionID != "" && fi.VersionID != nullVersionID {
		uv, err = uuid.Parse(fi.VersionID)
		if err != nil {
			return err
		}
	}

	var dd uuid.UUID
	if fi.DataDir != "" {
		dd, err = uuid.Parse(fi.DataDir)
		if err != nil {
			return err
		}
	}

	ventry := xlMetaV2Version{
		WrittenByVersion: globalVersionUnix,
	}

	if fi.Deleted {