return (extension ? "extension>" : "plugin>") + plugin.getGroupId() + ":" + plugin.getArtifactId() + ":"
                + version;
    }

    private static String getId(Artifact artifact) {
        return getId(
                artifact.getGroupId(),
                artifact.getArtifactId(),
                artifact.getExtension(),

        return getGroupId()
                + ':'
                + getArtifactId()
                + ':'
                + getExtension()
                + (c.isEmpty() ? "" : ":" + c)
                + ':'
                + getVersion();
    }

    /**
     * {@return the group identifier of the artifact}.
     *
     * @see ArtifactCoordinates#getGroupId()
     */
    @Nonnull

                }
                Artifact result = new RelocatedArtifact(
                        original,
                        isAny(relocation.target.getGroupId()) ? null : relocation.target.getGroupId(),
                        isAny(relocation.target.getArtifactId()) ? null : relocation.target.getArtifactId(),

                return step.name + "(" + step.project.getGroupId() + ":" + artifactId + ")";
            } else {
                return step.name + "(:" + artifactId + ")";
            }
        }
    }

    protected void mojo(Consumer<String> writer, MojoExecution mojoExecution) {
        String mojoExecId =
                mojoExecution.getGroupId() + ':' + mojoExecution.getArtifactId() + ':' + mojoExecution.getVersion()

        buffer.append(" {execution: ").append(executionId).append('}');
        return buffer.toString();
    }

    public String getGroupId() {
        if (mojoDescriptor != null) {
            return mojoDescriptor.getPluginDescriptor().getGroupId();
        }

        return plugin.getGroupId();
    }

    public String getArtifactId() {
        if (mojoDescriptor != null) {

                .map(Dependency::getArtifact)
                .filter(d -> "org.apache.maven".equals(d.getGroupId()))
                .filter(d -> !DefaultPluginValidationManager.EXPECTED_PROVIDED_SCOPE_EXCLUSIONS_GA.contains(
                        d.getGroupId() + ":" + d.getArtifactId()))
                .map(Artifact::getVersion)
                .collect(Collectors.toSet());

    public PluginNotFoundException(Plugin plugin, ArtifactNotFoundException e) {
        super(
                "Plugin could not be found - check that the goal name is correct: " + e.getMessage(),
                e.getGroupId(),
                e.getArtifactId(),
                e.getVersion(),
                "maven-plugin",
                null,
                e.getRemoteRepositories(),
                null,

        groupId = plugin.getGroupId();
        artifactId = plugin.getArtifactId();
    }

    DefaultPluginPrefixResult(String groupId, String artifactId, ArtifactRepository repository) {
        this.groupId = groupId;
        this.artifactId = artifactId;
        this.repository = repository;
    }

    @Override
    public String getGroupId() {
        return groupId;
    }

        source.setGroupId("source-group");
        source.setVersion("2.0");
        assertFalse(target.merge(source));
        assertEquals("myArtifact", target.getArtifactId());
        assertEquals("myGroup", target.getGroupId());
        assertEquals("1.0-SNAPSHOT", target.getVersion());
    }
    /*--- END test common metadata ---*/

    /*--- START test "groupId/artifactId/version" metadata ---*/
    @Test

                }
            }
        }
        return version;
    }

    public static String versionlessKey(Artifact artifact) {
        return versionlessKey(artifact.getGroupId(), artifact.getArtifactId());
    }

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