# Uuid.randomUuid constructor

Uuid.randomUuid()

Generates a random UUID (version 4).

Returns:

- A new random UUID with version 4 and variant 2 (RFC 4122)

## Security Properties

- Uses cryptographically secure random number generator
- 122 bits of entropy (6 bits reserved for version/variant)
- Suitable for security-sensitive applications
- Extremely low collision probability (2^-61 for 1 billion UUIDs)

## Performance

- O(1) generation time
- Thread-safe concurrent generation
- No external dependencies or network calls

## Example

    final uuid1 = Uuid.randomUuid();
    final uuid2 = Uuid.randomUuid();
    print(uuid1 != uuid2); // true (virtually guaranteed)
    print(uuid1.version); // 4

## Implementation

    factory Uuid.randomUuid() {
      final bytes = _rangeBuilder.generate();

      // Set version (4) and variant (2) bits
      bytes[6] = (bytes[6] & 0x0F) | 0x40; // Version 4
      bytes[8] = (bytes[8] & 0x3F) | 0x80; // Variant 2

      return Uuid._fromBytes(bytes);
    }