@Override
    public int getPageSize() {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        if (num == null) {
            num = fessConfig.getPagingSearchPageSizeAsInteger();
        } else {
            try {
                if (num.intValue() > fessConfig.getPagingSearchPageMaxSizeAsInteger().intValue() || num.intValue() <= 0) {
                    num = fessConfig.getPagingSearchPageMaxSizeAsInteger();

        if (start == null) {
            start = fessConfig.getPagingSearchPageStartAsInteger();
        }
        if (num == null) {
            num = fessConfig.getPagingSearchPageSizeAsInteger();
        } else if (num > fessConfig.getPagingSearchPageMaxSizeAsInteger().intValue()) {
            num = fessConfig.getPagingSearchPageMaxSizeAsInteger();
        }
    }

    @Override

  protected void update(ByteBuffer b) {
    if (b.hasArray()) {
      update(b.array(), b.arrayOffset() + b.position(), b.remaining());
      Java8Compatibility.position(b, b.limit());
    } else {
      for (int remaining = b.remaining(); remaining > 0; remaining--) {
        update(b.get());
      }
    }
  }

  /** Updates the sink with the given number of bytes from the buffer. */

    if (userPassedSupplier) {
      throw new AssertionError(
          "expected to throw "
              + expectedThrowable.getSimpleName()
              + " but returned result: "
              + result);
    } else {
      throw new AssertionError("expected to throw " + expectedThrowable.getSimpleName());
    }
  }

  private enum PlatformSpecificExceptionBatch {
    PLATFORM {
      @GwtIncompatible

                this.queryAddress.isDataFromNodeStatus = true;
                addrFound = true;
                this.addressArray[ i ] = this.queryAddress;
            }
            else {
                this.addressArray[ i ] = new NbtAddress(
                    new Name(this.config, n, hexCode, scope),
                    this.queryAddress.address,
                    groupName,

Isso ainda é suportado graças ao **Pydantic**, pois ele tem <a href="https://docs.pydantic.dev/latest/concepts/dataclasses/#use-of-stdlib-dataclasses-with-basemodel" class="external-link" target="_blank">suporte interno para `dataclasses`</a>.

Então, mesmo com o código acima que não usa Pydantic explicitamente, o FastAPI está usando Pydantic para converter essas dataclasses padrão para a versão do Pydantic.

E claro, ele suporta o mesmo:

* validação de dados

        return exception;
    }

    @Override
    public String getMessage() {
        String msg = null;

        if (message != null && !message.isEmpty()) {
            msg = message;
        } else if (exception != null) {
            msg = exception.getMessage();
        }

        if (msg == null) {
            msg = "";
        }

        return msg;
    }

    @Override

                modelId = "";
            }
            tmp.addModelId(modelId);
            tmp.setRawModel(modelId, model);
            tmp.setProblems(problems);
            result = tmp;
        } else {
            result = null;
        }
    }

    /**
     * Creates a new exception from the specified interim result and its associated problems.
     *

        ConcurrentHashMap<Object, Supplier<?>> cache;
        RepositoryCache repositoryCache = session.getCache();
        if (repositoryCache == null) {
            cache = new ConcurrentHashMap<>();
        } else {
            cache = (ConcurrentHashMap<Object, Supplier<?>>)
                    repositoryCache.computeIfAbsent(session, KEY, ConcurrentHashMap::new);
        }
        return new DefaultModelCache(cache);
    }

    Set<Feature<?>> features = computeMultimapAsMapGetFeatures(parentBuilder.getFeatures());
    if (Collections.disjoint(features, EnumSet.allOf(CollectionSize.class))) {
      return new TestSuite();
    } else {
      return ListTestSuiteBuilder.using(
              new MultimapAsMapGetGenerator<K, V>(parentBuilder.getSubjectGenerator()))
          .withFeatures(features)
          .named(parentBuilder.getName() + ".asMap[].get[key]")