So, it was a complete additional system.

It is not very popular or used nowadays.

## OpenAPI { #openapi }

OpenAPI (previously known as Swagger) is the open specification for building APIs (now part of the Linux Foundation).

**FastAPI** is based on **OpenAPI**.

That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.settings.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.

     * @param rootProject The root project that is being built.
     */
    void applyResumptionData(MavenExecutionRequest request, MavenProject rootProject);

    /**
     * Removes previously stored resumption data.
     * @param rootProject The root project that is being built.
     */
    void removeResumptionData(MavenProject rootProject);

              <include>org.apache.maven.toolchain.building</include>
              <include>org.apache.maven.toolchain.io</include>
              <include>org.apache.maven.toolchain.io.xpp3</include>
              <include>org.apache.maven.toolchain.merge</include>
            </includes>
            <excludes>

import org.apache.maven.execution.MavenSession;
import org.apache.maven.model.Repository;
import org.apache.maven.model.building.ModelBuildingException;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelSource;
import org.apache.maven.model.building.UrlModelSource;
import org.apache.maven.plugin.LegacySupport;
import org.apache.maven.profiles.ProfileManager;

 */
package org.apache.maven.model.building;

import java.io.File;
import java.util.Date;
import java.util.List;
import java.util.Properties;

import org.apache.maven.model.Model;
import org.apache.maven.model.Profile;
import org.apache.maven.model.resolution.ModelResolver;
import org.apache.maven.model.resolution.WorkspaceModelResolver;

/**

# This workflow will build a Java project with Maven
# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven

name: Java CI with Maven

on:
  push:
    branches: [ master ]
  pull_request:
    branches: [ master ]

jobs:
  build:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v4
    - name: Set up JDK 17

 * under the License.
 */
package org.apache.maven.model.building;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import static java.util.Collections.singleton;
import static org.apache.maven.model.building.ModelProblem.Severity.ERROR;
import static org.apache.maven.model.building.ModelProblem.Severity.FATAL;

/**

import org.apache.maven.model.Build;
import org.apache.maven.model.Dependency;
import org.apache.maven.model.Model;
import org.apache.maven.model.Plugin;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;
import org.codehaus.plexus.util.StringUtils;

/**
 * Handles normalization of a model.
 *

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.settings.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.