in maven-plugin-testing-harness/src/main/java/org/apache/maven/plugin/testing/ArtifactStubFactory.java [333:341]
public Set<Artifact> getTypedArtifacts() throws IOException {
Set<Artifact> set = new HashSet<>();
set.add(createArtifact("g", "a", "1.0", Artifact.SCOPE_COMPILE, "war", null));
set.add(createArtifact("g", "b", "1.0", Artifact.SCOPE_COMPILE, "jar", null));
set.add(createArtifact("g", "c", "1.0", Artifact.SCOPE_COMPILE, "sources", null));
set.add(createArtifact("g", "d", "1.0", Artifact.SCOPE_COMPILE, "zip", null));
set.add(createArtifact("g", "e", "1.0", Artifact.SCOPE_COMPILE, "rar", null));
return set;
}