//// tab | Annotated

```Python
q: Annotated[str | None, Query(min_length=3)] = None
```

////

So, when you need to declare a value as required while using `Query`, you can simply not declare a default value:

{* ../../docs_src/query_params_str_validations/tutorial006_an_py39.py hl[9] *}

### Required, can be `None` { #required-can-be-none }

    checkNotNull(comparator);
    if (!elements.hasNext()) {
      return emptySet(comparator);
    }
    SortedSet<E> delegate = new TreeSet<E>(comparator);
    while (elements.hasNext()) {
      E element = elements.next();
      checkNotNull(element);
      delegate.add(element);
    }
    return new RegularImmutableSortedSet<E>(delegate, false);
  }

      File file = getFile();
      InputStream in = new FileInputStream(file);
      ByteArrayOutputStream out = new ByteArrayOutputStream();
      byte[] buffer = new byte[100];
      int read;
      while ((read = in.read(buffer)) != -1) {
        out.write(buffer, 0, read);
      }
      return out.toByteArray();
    }
  }

        field.setAccessible(true);
        field.set(obj, value);
    }

    private Field getField(Class<?> clazz, String fieldName) throws NoSuchFieldException {
        while (clazz != null) {
            try {
                return clazz.getDeclaredField(fieldName);
            } catch (NoSuchFieldException e) {
                clazz = clazz.getSuperclass();
            }
        }

    // 1. Asterisk (*) is only permitted in the left-most domain name label and must be the
    //    only character in that label (i.e., must match the whole left-most label).
    //    For example, *.example.com is permitted, while *a.example.com, a*.example.com,
    //    a*b.example.com, a.*.example.com are not permitted.
    // 2. Asterisk (*) cannot match across domain name labels.

  }

  /** Returns a callable that reads all of source, closes it, and returns the bytes.  */
  private fun sourceReader(source: Source?): Callable<ByteString> =
    Callable {
      val buffer = Buffer()
      while (source!!.read(buffer, 16384) != -1L) {
      }
      source.close()
      buffer.readByteString()
    }

  private fun assertFile(
    prefix: ByteString,
    upstreamSize: Long,

    for (int z = 0; z < 100; z++) {
      int[] codePoints = new int[rng.nextInt(8)];
      for (int i = 0; i < codePoints.length; i++) {
        do {
          codePoints[i] = rng.nextInt(0x800);
        } while (!Character.isValidCodePoint(codePoints[i])
            || (codePoints[i] >= Character.MIN_SURROGATE
                && codePoints[i] <= Character.MAX_SURROGATE));
      }
      StringBuilder builder = new StringBuilder();

      weakHashLength32WithSeeds(bytes, offset + 32, z + w[1], y, w);
      long tmp = z;
      z = x;
      x = tmp;
      offset += 64;
      length -= 64;
    } while (length != 0);
    return hash128to64(hash128to64(v[0], w[0]) + shiftMix(y) * K1 + z, hash128to64(v[1], w[1]) + x);
  }

  private static long hashLength33To64(byte[] bytes, int offset, int length) {

            int i, len, dots;
            char[] data;

            i = dots = 0; /* quick IP address validation */
            len = hostname.length();
            data = hostname.toCharArray();
            while (i < len && Character.isDigit(data[i++])) {
                if (i == len && dots == 3) {
                    // probably an IP address
                    return true;
                }

            this.modelInterpolator = modelInterpolator;
            this.logger = logger;
        }

        @Override
        public ModelInterpolationException run() {
            while (!interpolationTargets.isEmpty()) {
                Object obj = interpolationTargets.removeFirst();

                try {
                    traverseObjectWithParents(obj.getClass(), obj);