<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> là một thư viện Python để validate dữ liệu hiệu năng cao.

Bạn có thể khai báo "hình dạng" của dữa liệu như là các lớp với các thuộc tính.

Và mỗi thuộc tính có một kiểu dữ liệu.

   * Returns the element at the specified position in an iterable or a default value otherwise.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code
   * stream.skip(position).findFirst().orElse(defaultValue)} (returns the default value if the index
   * is out of bounds)
   *
   * @param position position of the element to return
   * @param defaultValue the default value to return if {@code position} is greater than or equal to

    }
    return max;
  }

  /**
   * Returns the value nearest to {@code value} which is within the closed range {@code [min..max]}.
   *
   * <p>If {@code value} is within the range {@code [min..max]}, {@code value} is returned
   * unchanged. If {@code value} is less than {@code min}, {@code min} is returned, and if {@code
   * value} is greater than {@code max}, {@code max} is returned.
   *

    NODE_UNAVAILABLE(6),      // Cluster node unavailable
    NODE_AVAILABLE(7);        // Cluster node available
    
    private final int value;
    
    WitnessEventType(int value) {
        this.value = value;
    }
    
    public int getValue() { return value; }
}
```

## 4. Data Structures

### 4.1 Witness Registration
```java
package jcifs.internal.witness;

import java.net.InetAddress;

			selected = entry
			continue
		}

		// Get new entry metadata,
		// shallow decode.
		xl, err := entry.xlmeta()
		if err != nil {
			continue
		}
		objsValid++

		// Add all valid to candidates.
		r.candidates = append(r.candidates, xl.versions)

		// We select the first object we find as a candidate and see if all match that.
		// This is to quickly identify if all agree.
		if selected == nil {

Another big feature needed by APIs is data validation, making sure that the data is valid, given certain parameters. For example, that some field is an `int`, and not some random string. This is especially useful for incoming data.

Without a data validation system, you would have to do all the checks by hand, in code.

    containing an IP address we must match that address against the URL's IP address, even when the
    two addresses are encoded differently, such as `192.168.1.1` and `0::0:0:FFFF:C0A8:101`. Note
    that OkHttp incorrectly rejected valid certificates resulting in a failure to connect; at no
    point were invalid certificates accepted.
 *  New: `OkHttpClient.Builder.minWebSocketMessageToCompress()` configures a threshold for

      // In the first case, any long is valid; in the second, we want to test that the next-bigger
      // long overflows.
    }
    int k = LongMath.biggestBinomials.length;
    assertFalse(fitsInLong(BigIntegerMath.binomial(2 * k, k)));
    // 2 * k is the smallest value for which we don't replace k with (n-k).
  }

  @GwtIncompatible // TODO

  public void testHashCode() {
    for (double value : VALUES) {
      assertThat(Doubles.hashCode(value)).isEqualTo(Double.hashCode(value));
    }
  }

  @SuppressWarnings("InlineMeInliner") // We need to test our method.
  public void testIsFinite() {
    for (double value : NUMBERS) {
      assertThat(Doubles.isFinite(value)).isEqualTo(Double.isFinite(value));
    }
  }

	if err := tw.writeRawHeader(&tw.blk, int64(len(data)), flag); err != nil {
		return err
	}
	_, err := io.WriteString(tw, data)
	return err
}

// writeRawHeader writes the value of blk, regardless of its value.
// It sets up the Writer such that it can accept a file of the given size.
// If the flag is a special header-only flag, then the size is treated as zero.