{* ../../docs_src/query_params_str_validations/tutorial014_an_py310.py hl[10] *}

## Custom Validation { #custom-validation }

There could be cases where you need to do some **custom validation** that can't be done with the parameters shown above.

In those cases, you can use a **custom validator function** that is applied after the normal validation (e.g. after validating that the value is a `str`).

You can verify it in the docs UI at `/docs`:

<div class="screenshot">
<img src="/img/tutorial/request-form-models/image01.png">
</div>

## Forbid Extra Form Fields { #forbid-extra-form-fields }

In some special use cases (probably not very common), you might want to **restrict** the form fields to only those declared in the Pydantic model. And **forbid** any **extra** fields.

/// note

This is supported since FastAPI version `0.114.0`. 🤓

   * running the same hash function on the equivalent input. For cross-language compatibility, use
   * {@link #putString}, usually with a charset of UTF-8. For other use cases, use {@code
   * putUnencodedChars}.
   *
   * @since 15.0 (since 11.0 as putString(CharSequence)).
   */
  @CanIgnoreReturnValue
  @Override
  Hasher putUnencodedChars(CharSequence charSequence);

		return nil, errInvalidRange
	}
	return hrange, nil
}

// checkCopyPartRangeWithSize adds more check to the range string in case of
// copy object part. This API requires having specific start and end  range values
// e.g. 'bytes=3-10'. Other use cases will be rejected.
func checkCopyPartRangeWithSize(rs *HTTPRangeSpec, resourceSize int64) (err error) {
	if rs == nil {
		return nil
	}

   */
  public void testIsWellFormed_4BytesSamples() {
    // Valid 4 byte.
    assertWellFormed(0xF0, 0xA4, 0xAD, 0xA2);
    // Bad trailing bytes
    assertNotWellFormed(0xF0, 0xA4, 0xAD, 0x7F);
    assertNotWellFormed(0xF0, 0xA4, 0xAD, 0xC0);
    // Special cases for byte2
    assertNotWellFormed(0xF0, 0x8F, 0xAD, 0xA2);

In these cases you can use `root_path` to configure your application.

The `root_path` is a mechanism provided by the ASGI specification (that FastAPI is built on, through Starlette).

The `root_path` is used to handle these specific cases.

And it's also used internally when mounting sub-applications.

		isValidBucketName := IsValidBucketName(testCase.bucketName)
		if testCase.shouldPass && !isValidBucketName {
			t.Errorf("Test case %d: Expected \"%s\" to be a valid bucket name", i+1, testCase.bucketName)
		}
		if !testCase.shouldPass && isValidBucketName {
			t.Errorf("Test case %d: Expected bucket name \"%s\" to be invalid", i+1, testCase.bucketName)
		}
	}
}

// Tests for validate object name.

//
// In most cases, new([Buffer]) (or just declaring a [Buffer] variable) is
// sufficient to initialize a [Buffer].
func NewBuffer(buf []byte) *Buffer { return &Buffer{buf: buf} }

// NewBufferString creates and initializes a new [Buffer] using string s as its
// initial contents. It is intended to prepare a buffer to read an existing
// string.
//

### Certificate Renewal { #certificate-renewal }

At some point in the future, each certificate would **expire** (about 3 months after acquiring it).

And then, there would be another program (in some cases it's another program, in some cases it could be the same TLS Termination Proxy) that would talk to Let's Encrypt, and renew the certificate(s).

package jcifs.smb1.smb1;

/**
 * Unit tests for {@link FileEntry}. The interface itself has no
 * implementation, so the tests exercise the contract via Mockito mocks.
 * Each method is exercised for normal inputs, extreme or edge cases, and
 * interaction verification.
 */
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.mockito.Mockito.mock;