switch op {
	case opIs:
		if a.IsNull() {
			// Missing is null
			return v.IsNull() || v.IsMissing(), nil
		}
		if a.IsMissing() {
			return v.IsMissing(), nil
		}
		// Forward to Equal
		op = opEq
	case opIsNot:
		if a.IsNull() {
			// Missing is not null
			return !v.IsNull() && !v.IsMissing(), nil
		}
		if a.IsMissing() {
			return !v.IsMissing(), nil
		}
		// Forward to not equal.

    client = TestClient(app)
    response = client.get(path)
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["header", "p"],
                "msg": "Field required",
                "input": AnyThing,
            }
        ]
    }


@pytest.mark.parametrize(
    "path",

                new PluginParameterException(mojoDescriptor, Collections.singletonList(parameter));

        assertEquals(
                "One or more required plugin parameters are invalid/missing for 'goalPrefix:goal'" + LS
                        + LS + "[0] Inside the definition for plugin 'artifactId', specify the following:"
                        + LS
                        + LS + "<configuration>"

- artifact metadata missing
- extension metadata missing
- extension artifact missing
- artifact metadata retrieval problem
- version range violation
- circular dependency
- artifact missing
- artifact retrieval exception
- md5 checksum doesn't match for local artifact, need to redownload this
- POM doesn't exist for a goal that requires one
- parent POM missing (in both the repository + relative path)

    /**
     * @param originatingArtifact the artifact that was being resolved
     * @param missingArtifacts    artifacts that could not be resolved
     * @param remoteRepositories  remote repositories where the missing artifacts were not found
     * @deprecated use {@link #MultipleArtifactsNotFoundException(Artifact, List, List, List)}
     */
    @Deprecated
    public MultipleArtifactsNotFoundException(

    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["query", "token"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",
                "loc": ["header", "x-token"],
                "msg": "Field required",
                "input": None,

    client = TestClient(app)
    response = client.post(path, json=json)
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": IsOneOf(["body"], ["body", "p"]),
                "msg": "Field required",
                "input": IsOneOf(None, {}),
            }
        ]
    }


@pytest.mark.parametrize(

    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["header", "x-token"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",
                "loc": ["header", "x-key"],
                "msg": "Field required",
                "input": None,

client = TestClient(app)


def test_query():
    response = client.get("/query")
    assert response.status_code == 422
    assert response.json() == {
        "detail": [
            {
                "type": "missing",
                "loc": ["query", "query"],
                "msg": "Field required",
                "input": None,
            }
        ]
    }


def test_query_query_baz():

		}
	}

	if reflect.DeepEqual(s1.MinioEnv, s2.MinioEnv) {
		return nil
	}

	// Report differences in environment variables.
	var missing []string
	var mismatching []string
	for k, v := range s1.MinioEnv {
		ev, ok := s2.MinioEnv[k]
		if !ok {
			missing = append(missing, k)
		} else if v != ev {
			mismatching = append(mismatching, k)
		}
	}
	var extra []string
	for k := range s2.MinioEnv {