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

## Forbid Extra Query Parameters { #forbid-extra-query-parameters }

In some special use cases (probably not very common), you might want to **restrict** the query parameters that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

   * to this supplier.
   *
   * <p><b>Warning: do not depend</b> on the behavior of this method.
   *
   * <p>Historically, {@code Supplier} instances in this library have implemented this method to
   * recognize certain cases where distinct {@code Supplier} instances would in fact behave
   * identically. However, as code migrates to {@code java.util.function}, that behavior will
   * disappear. It is best not to depend on it.
   */
  @Override

This also means that in many cases you can pass the same object you get from a request **directly to the database**, as everything is validated automatically.

The same applies the other way around, in many cases you can just pass the object you get from the database **directly to the client**.

{* ../../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`).

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Test cases for {@link Tables#transformValues}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public class TablesTransformValuesTest extends AbstractTableTest<Character> {

   * to this supplier.
   *
   * <p><b>Warning: do not depend</b> on the behavior of this method.
   *
   * <p>Historically, {@code Supplier} instances in this library have implemented this method to
   * recognize certain cases where distinct {@code Supplier} instances would in fact behave
   * identically. However, as code migrates to {@code java.util.function}, that behavior will
   * disappear. It is best not to depend on it.
   */
  @Override

	}
	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
	}
	if rs.IsSuffixLength || rs.Start >= resourceSize || rs.End >= resourceSize {

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import "testing"

// Test parseCopyPartRange()
func TestParseCopyPartRangeSpec(t *testing.T) {
	// Test success cases.
	successCases := []struct {
		rangeString string
		offsetBegin int64
		offsetEnd   int64
	}{
		{"bytes=2-5", 2, 5},
		{"bytes=2-9", 2, 9},
		{"bytes=2-2", 2, 2},
		{"bytes=0000-0006", 0, 6},
	}

# Distributed Server Design Guide [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io)

This document explains the design, architecture and advanced use cases of the MinIO distributed server.

## Command-line

```
NAME:
  minio server - start object storage server

USAGE:
  minio server [FLAGS] DIR1 [DIR2..]
  minio server [FLAGS] DIR{1...64}
  minio server [FLAGS] DIR{1...64} DIR{65...128}

DIR:

//
// 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.
//