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.
		op = opIneq
	default:

        checkArtifactResult(artifactResult, "artifact-1.0-classifier.zip");
    }

    private void checkArtifactResult(ArtifactResult result, String filename) {
        assertFalse(result.isMissing(), "Expected " + result + ".isMissing() to return false");
        assertTrue(result.isResolved(), "Expected " + result + ".isResolved() to return true");
        Artifact artifact = result.getArtifact();
        assertNotNull(artifact.getFile());

         *
         * @return {@code true} if the artifact is not present in any repository, {@code false} otherwise.
         */
        boolean isMissing();
    }

		v = i
	} else if t, ok := value.ToTimestamp(); ok {
		v = sql.FormatSQLTimestamp(t)
	} else if s, ok := value.ToString(); ok {
		v = s
	} else if value.IsNull() {
		v = nil
	} else if value.IsMissing() {
		return r, nil
	} else if b, ok := value.ToBytes(); ok {
		// This can either be raw json or a CSV value.
		// Only treat objects and arrays as JSON.
		if len(b) > 0 && (b[0] == '{' || b[0] == '[') {

                localProject = resItem.getRepository() instanceof org.apache.maven.api.WorkspaceRepository;
            } catch (ArtifactResolverException e) {
                if (e.getResult().getResults().values().iterator().next().isMissing() && allowStubModel) {
                    return build(parent, null, createStubModelSource(artifact));
                }
                throw new ProjectBuildingException(