}

    public static String key(String groupId, String artifactId, String version) {
        notBlank(groupId, "groupId can neither be null, empty nor blank");
        notBlank(artifactId, "artifactId can neither be null, empty nor blank");
        notBlank(version, "version can neither be null, empty nor blank");

        return groupId + ":" + artifactId + ":" + version;
    }

    private static void notBlank(String str, String message) {

                value = basedir + expression.substring(pathSeparator);
            }
        }

        /*
         * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
         * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to

import static org.junit.jupiter.api.Assertions.assertNull;

class MavenModelMergerTest {
    private MavenModelMerger modelMerger = new MavenModelMerger();

    // modelVersion is neither inherited nor injected
    @Test
    void testMergeModel_ModelVersion() {
        Model parent = Model.newBuilder().modelVersion("4.0.0").build();
        Model model = Model.newInstance();

     *
     * @return the activated file model, never {@code null}.
     */
    @Nonnull
    Model getActivatedFileModel();

    /**
     * Gets the file model + build pom transformation, without inheritance nor interpolation.
     *
     * @return The raw model, never {@code null}.
     */
    @Nonnull
    Model getRawModel();

    /**
     * Gets the assembled model with inheritance, interpolation and profile injection.

        context.setValue(expression, value);
    }

    /*
    public int containerCountForUri( String uri )
        throws IOException
    {
        Validate.notEmpty( uri, "uri can neither be null nor empty " );
        ModelDataSource source = new DefaultModelDataSource();
        source.init( domainModel.getModelProperties(), null );
        return source.queryFor( uri ).size();
    }
    */

        // neither inherited nor injected
    }

    @Override
    protected void mergeModel_ArtifactId(
            Model.Builder builder, Model target, Model source, boolean sourceDominant, Map<Object, Object> context) {
        // neither inherited nor injected
    }

    @Override
    protected void mergeModel_Profiles(

                }
            }
        }

        /*
         * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
         * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to