Let's take this application as example:

{* ../../docs_src/query_params_str_validations/tutorial001_py310.py hl[7] *}

The query parameter `q` is of type `str | None`, that means that it's of type `str` but could also be `None`, and indeed, the default value is `None`, so FastAPI will know it's not required.

/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

    fun edit(): Editor? = ******@****.***(key, sequenceNumber)

    /** Returns the unbuffered stream with the value for [index]. */
    fun getSource(index: Int): Source = sources[index]

    /** Returns the byte length of the value for [index]. */
    fun getLength(index: Int): Long = lengths[index]

    override fun close() {
      for (source in sources) {
        source.closeQuietly()
      }
    }
  }

    int startingIndex = smear(c) & mask;
    int index = startingIndex;
    do {
      if (table[index] == 0) { // Check for empty.
        return false;
      } else if (table[index] == c) { // Check for match.
        return true;
      } else { // Linear probing.
        index = (index + 1) & mask;
      }
      // Check to see if we wrapped around the whole table.
    } while (index != startingIndex);
    return false;
  }

     * @return The file type helper.
     */
    public static FileTypeHelper getFileTypeHelper() {
        return getComponent(FILE_TYPE_HELPER);
    }

    /**
     * Gets the index updater component.
     * @return The index updater.
     */
    public static IndexUpdater getIndexUpdater() {
        return getComponent(INDEX_UPDATER);
    }

    /**
     * Gets the key match helper component.

import org.opensearch.index.query.MoreLikeThisQueryBuilder;
import org.opensearch.index.query.PrefixQueryBuilder;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.index.query.QueryStringQueryBuilder;
import org.opensearch.index.query.RangeQueryBuilder;
import org.opensearch.index.query.RegexpQueryBuilder;
import org.opensearch.index.query.SpanTermQueryBuilder;

import org.opensearch.index.query.MoreLikeThisQueryBuilder;
import org.opensearch.index.query.PrefixQueryBuilder;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.index.query.QueryStringQueryBuilder;
import org.opensearch.index.query.RangeQueryBuilder;
import org.opensearch.index.query.RegexpQueryBuilder;
import org.opensearch.index.query.SpanTermQueryBuilder;

    assertEquals(0, Iterables.indexOf(list, equalTo("mary")));
    assertEquals(1, Iterables.indexOf(list, equalTo("bob")));
    assertEquals(-1, Iterables.indexOf(list, equalTo("jack")));
  }

  public void testIndexOf_withDuplicates() {
    List<String> list = Lists.newArrayList("mary", "bob", "bob", "bob", "sam");
    assertEquals(0, Iterables.indexOf(list, equalTo("mary")));

import org.opensearch.index.query.RangeQueryBuilder;
import org.opensearch.index.query.RegexpQueryBuilder;
import org.opensearch.index.query.SpanTermQueryBuilder;
import org.opensearch.index.query.TermQueryBuilder;
import org.opensearch.index.query.TermsQueryBuilder;
import org.opensearch.index.query.WildcardQueryBuilder;
import org.opensearch.index.query.functionscore.FunctionScoreQueryBuilder;

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public abstract class AbstractListIndexOfTester<E> extends AbstractListTester<E> {
  /** Override to call {@code indexOf()} or {@code lastIndexOf()}. */
  protected abstract int find(@Nullable Object o);

  /** Override to return "indexOf" or "lastIndexOf()" for use in failure messages. */
  protected abstract String getMethodName();

  @CollectionSize.Require(absent = ZERO)

    int index = off;
    while (true) {
      int byte1;

      // Optimize for interior runs of ASCII bytes.
      do {
        if (index >= end) {
          return true;
        }
      } while ((byte1 = bytes[index++]) >= 0);

      if (byte1 < (byte) 0xE0) {
        // Two-byte form.
        if (index == end) {
          return false;
        }