import org.gradle.internal.service.scopes.Scope;
import org.gradle.internal.service.scopes.ServiceScope;

import java.util.Map;

@ServiceScope(Scope.Build.class)
public interface ProjectPropertiesLoader {

    Map<String, Object> loadProjectProperties();

        }
        getVariables() >> Mock(Environment.Properties) {
            byNamePrefix(ENV_PROJECT_PROPERTIES_PREFIX) >> { prefixedEnvironmentVariables }
        }
    }

    private final ProjectPropertiesLoader projectPropertiesLoader = new DefaultProjectPropertiesLoader(startParameter, environment)

    def "load properties from environment variables with prefix"() {
        given:
        prefixedEnvironmentVariables = [

        def gradlePropertiesLoader = new DefaultGradlePropertiesLoader(startParameter, environment)
        def projectPropertiesLoader = new DefaultProjectPropertiesLoader(startParameter, environment)
        def controller = new DefaultGradlePropertiesController(gradlePropertiesLoader, Mock(SystemPropertiesInstaller), projectPropertiesLoader)
        def properties = controller.gradleProperties

        when:

    private final SystemPropertiesInstaller systemPropertiesInstaller;
    private final ProjectPropertiesLoader projectPropertiesLoader;

    public DefaultGradlePropertiesController(IGradlePropertiesLoader propertiesLoader, SystemPropertiesInstaller systemPropertiesInstaller, ProjectPropertiesLoader projectPropertiesLoader) {
        this.propertiesLoader = propertiesLoader;

        SystemPropertiesInstaller systemPropertiesInstaller,
        ProjectPropertiesLoader projectPropertiesLoader
    ) {
        return new DefaultGradlePropertiesController(propertiesLoader, systemPropertiesInstaller, projectPropertiesLoader);
    }

    @Provides
    protected ProjectPropertiesLoader createProjectPropertiesLoader(
        Environment environment
    ) {

import static org.gradle.initialization.IGradlePropertiesLoader.SYSTEM_PROJECT_PROPERTIES_PREFIX;

public class DefaultProjectPropertiesLoader implements ProjectPropertiesLoader {

    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultProjectPropertiesLoader.class);

    private final Environment environment;

    private final StartParameterInternal startParameter;

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