import org.gradle.internal.component.external.model.ProjectDerivedCapability;
import org.gradle.internal.deprecation.DeprecationLogger;

import java.util.LinkedHashSet;
import java.util.Set;

public class DefaultJavaFeatureSpec implements FeatureSpec {
    private final String name;
    private final Set<Capability> capabilities = new LinkedHashSet<>(1);
    private final ProjectInternal project;

    private SourceSet sourceSet;

     */
    @Override
    public void registerFeature(String name, Action<? super FeatureSpec> configureAction) {
        DefaultJavaFeatureSpec spec = new DefaultJavaFeatureSpec(validateFeatureName(name), project);
        configureAction.execute(spec);
        JvmFeatureInternal feature = spec.create();

Class <org.gradle.api.plugins.internal.DefaultJavaFeatureSpec> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (DefaultJavaFeatureSpec.java:0)