{* ../../docs_src/query_params/tutorial004_py310.py hl[6,8] *}

## Required query parameters { #required-query-parameters }

When you declare a default value for non-path parameters (for now, we have only seen query parameters), then it is not required.

If you don't want to add a specific value but just make it optional, set the default as `None`.

Let's imagine that loading the model can **take quite some time**, because it has to read a lot of **data from disk**. So you don't want to do it for every request.

You could load it at the top level of the module/file, but that would also mean that it would **load the model** even if you are just running a simple automated test, then that test would be **slow** because it would have to wait for the model to load before being able to run an independent part of the code.

      "options": {
        "colorMode": "value",
        "graphMode": "area",
        "justifyMode": "auto",
        "orientation": "auto",
        "reduceOptions": {
          "calcs": [
            "mean"
          ],
          "fields": "",
          "values": false
        },
        "showPercentChange": false,
        "text": {},
        "textMode": "auto",
        "wideLayout": true
      },

 * your own escapers extend this class and implement the {@link #escape(char)} method.
 *
 * @author Sven Mawson
 * @since 15.0
 */
@GwtCompatible
@SuppressWarnings("EscapedEntity") // We do mean for the user to see "<" etc.
public abstract class CharEscaper extends Escaper {
  /** Constructor for use by subclasses. */
  protected CharEscaper() {}

  /**
   * Returns the escaped form of a given literal string.

	rows, ok := tx.Statement.Dest.(*sql.Rows)
	if !ok && tx.DryRun && tx.Error == nil {
		tx.Error = ErrDryRunModeUnsupported
	}
	return rows, tx.Error
}

// Scan scans selected value to the struct dest
func (db *DB) Scan(dest interface{}) (tx *DB) {
	config := *db.Config
	currentLogger, newLogger := config.Logger, logger.Recorder.New()
	config.Logger = newLogger

	tx = db.getInstance()

pkg crypto/x509, method (OID) String() string #60665
pkg crypto/x509, type Certificate struct, Policies []OID #60665
pkg crypto/x509, type OID struct #60665
pkg database/sql, method (*Null[$0]) Scan(interface{}) error #60370
pkg database/sql, method (Null[$0]) Value() (driver.Value, error) #60370
pkg database/sql, type Null[$0 interface{}] struct #60370
pkg database/sql, type Null[$0 interface{}] struct, V $0 #60370

	result := make(map[string]string)

	mountInfo, err := os.Open("/proc/self/mountinfo")
	if err != nil {
		return nil, err
	}
	defer mountInfo.Close()

	scanner := bufio.NewScanner(mountInfo)
	for scanner.Scan() {
		s := strings.Split(scanner.Text(), " ")
		if len(s) != 11 {
			return nil, errors.New("unsupported /proc/self/mountinfo format")
		}
		result[s[2]] = s[9]
	}

	if err := scanner.Err(); err != nil {

     *       object associated with our thread, because if it was the publication wouldn't have been
     *       unsafe and we'd have seen our thread as the value. This state is also why a new
     *       ThreadConfinedTaskQueue object must be created for each inline execution, because
     *       observing a null thread does not mean the object is safe to reuse.
     *   <li>If this field's value is some other thread object, we know that it's not our thread.

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

        assertEquals(params, testSearcher.lastParams);
        assertEquals(userBean, testSearcher.lastUserBean);
    }

    public void test_search_withUserBean() {
        // Test search with user bean present
        TestRankFusionSearcher testSearcher = new TestRankFusionSearcher();
        String query = "user query";
        SearchRequestParams params = createTestSearchRequestParams();