if err != nil {
		t.Fatalf("failed to parse schema, got error %v", err)
	}

	if len(userSchema.Relationships.Relations) != 1 {
		t.Fatalf("expects 1 relations, but got %v", len(userSchema.Relationships.Relations))
	}

	if createdByRel, ok := userSchema.Relationships.Relations["CreatedBy"]; ok {
		if createdByRel.FieldSchema != userSchema {

}

func (schema *Schema) setRelation(relation *Relationship) {
	// set non-embedded relation
	if rel := schema.Relationships.Relations[relation.Name]; rel != nil {
		if len(rel.Field.BindNames) > 1 {
			schema.Relationships.Relations[relation.Name] = relation
		}
	} else {
		schema.Relationships.Relations[relation.Name] = relation
	}

	// set embedded relation
	if len(relation.Field.EmbeddedBindNames) <= 1 {
		return

	}
	names := make([]string, 0, len(embeddedRelations.Relations)+len(embeddedRelations.EmbeddedRelations))
	for _, relation := range embeddedRelations.Relations {
		// skip first struct name
		names = append(names, strings.Join(relation.Field.EmbeddedBindNames[1:], "."))
	}
	for _, relations := range embeddedRelations.EmbeddedRelations {
		names = append(names, embeddedValues(relations)...)
	}
	return names
}

			for _, join := range db.Statement.Joins {
				if db.Statement.Schema != nil {
					var isRelations bool // is relations or raw sql
					var relations []*schema.Relationship
					relation, ok := db.Statement.Schema.Relationships.Relations[join.Name]
					if ok {
						isRelations = true
						relations = append(relations, relation)
					} else {
						// handle nested join like "Manager.Company"

		if f.Size == 0 {
			f.Size = ref.ForeignKey.Size
		}
		ref.ForeignKey = f
	}

	for name, rel := range relation.JoinTable.Relationships.Relations {
		if _, ok := joinSchema.Relationships.Relations[name]; !ok {
			rel.Schema = joinSchema
			joinSchema.Relationships.Relations[name] = rel
		}
	}
	relation.JoinTable = joinSchema

	return nil
}

// Use use plugin
func (db *DB) Use(plugin Plugin) error {

  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.ObjectMeta metadata = 1;

  // spec contains the certificate request, and is immutable after creation.
  // Only the request, signerName, expirationSeconds, and usages fields can be set on creation.
  // Other fields are derived by Kubernetes and cannot be modified by users.
  optional CertificateSigningRequestSpec spec = 2;

A common pattern is to use an "ORM": an "object-relational mapping" library.

An ORM has tools to convert ("*map*") between *objects* in code and database tables ("*relations*").

With an ORM, you normally create a class that represents a table in a SQL database, each attribute of the class represents a column, with a name and a type.

For example a class `Pet` could represent a SQL table `pets`.

						if rel, ok := sch.Relationships.Relations[names[0]]; ok {
							subNameCount := len(names)
							// nested relation fields
							relFields := make([]*schema.Field, 0, subNameCount-1)
							relFields = append(relFields, rel.Field)
							for _, name := range names[1 : subNameCount-1] {
								rel = rel.FieldSchema.Relationships.Relations[name]
								relFields = append(relFields, rel.Field)
							}

            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.SERIALIZABLE_INCLUDING_VIEWS,
                CollectionFeature.KNOWN_ORDER,
                MapFeature.REJECTS_DUPLICATES_AT_CREATION,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .named("ImmutableMap")
            .createTestSuite());

    suite.addTest(
        MapTestSuiteBuilder.using(new ImmutableMapCopyOfGenerator())

                MapFeature.REJECTS_DUPLICATES_AT_CREATION,
                MapFeature.ALLOWS_ANY_NULL_QUERIES)
            .suppressing(BiMapInverseTester.getInverseSameAfterSerializingMethods())
            .createTestSuite());
    suite.addTestSuite(ImmutableBiMapTest.class);

    return suite;
  }

  // Creation tests

  public void testEmptyBuilder() {