### Documentação da API

Se você acessar a documentação da API, verá que ela tem os **schemas** para os dados a serem enviados nas requisições e recebidos nas respostas:

<img src="/img/tutorial/generate-clients/image01.png">

Você pode ver esses schemas porque eles foram declarados com os modelos no app.

Essas informações estão disponíveis no **OpenAPI schema** do app e são mostradas na documentação da API (pelo Swagger UI).

     *
     * @param schema
     *            {@link Source} to load the W3C XML Schema. Must not be {@literal null}.
     * @return {@link Schema}
     */
    public static Schema newW3cXmlSchema(final Source schema) {
        assertArgumentNotNull("schema", schema);
        return newSchema(SchemaFactoryUtil.newW3cXmlSchemaFactory(), schema);
    }

    /**

			relation.Type = HasMany
		}
	}

	if schema.err == nil {
		schema.setRelation(relation)
		switch relation.Type {
		case HasOne:
			schema.Relationships.HasOne = append(schema.Relationships.HasOne, relation)
		case HasMany:
			schema.Relationships.HasMany = append(schema.Relationships.HasMany, relation)
		case BelongsTo:
			schema.Relationships.BelongsTo = append(schema.Relationships.BelongsTo, relation)
		case Many2Many:

			for _, rel := range dep.Schema.Relationships.Relations {
				if rel.Field.IgnoreMigration {
					continue
				}
				if c := rel.ParseConstraint(); c != nil && c.Schema == dep.Statement.Schema && c.Schema != c.ReferenceSchema {
					dep.Depends = append(dep.Depends, c.ReferenceSchema)
				}

				if rel.Type == schema.HasOne || rel.Type == schema.HasMany {
					beDependedOn[rel.FieldSchema] = true
				}

			return
		}

		var (
			pkField     *schema.Field
			pkFieldName = "@id"
		)

		if db.Statement.Schema != nil {
			if db.Statement.Schema.PrioritizedPrimaryField == nil ||
				!db.Statement.Schema.PrioritizedPrimaryField.HasDefaultValue ||
				!db.Statement.Schema.PrioritizedPrimaryField.Readable {
				return
			}
			pkField = db.Statement.Schema.PrioritizedPrimaryField

			return
		}

		if db.Statement.Schema != nil {
			for _, c := range db.Statement.Schema.DeleteClauses {
				db.Statement.AddClause(c)
			}
		}

		if db.Statement.SQL.Len() == 0 {
			db.Statement.SQL.Grow(100)
			db.Statement.AddClauseIfNotExists(clause.Delete{})

			if db.Statement.Schema != nil {

				case reflect.Slice:
					queryFields = db.Statement.ReflectValue.Type().Elem() != db.Statement.Schema.ModelType
				}
			}

			if queryFields {
				stmt := gorm.Statement{DB: db}
				// smaller struct
				if err := stmt.Parse(db.Statement.Dest); err == nil && (db.QueryFields || stmt.Schema.ModelType != db.Statement.Schema.ModelType) {

}

// ParseUniqueConstraints parse schema unique constraints
func (schema *Schema) ParseUniqueConstraints() map[string]UniqueConstraint {
	uniques := make(map[string]UniqueConstraint)
	for _, field := range schema.Fields {
		if field.Unique {
			name := schema.namer.UniqueName(schema.Table, field.DBName)
			uniques[name] = UniqueConstraint{Name: name, Field: field}
		}
	}

	}

	checkUserSchema(t, user)
}

func checkUserSchema(t *testing.T, user *schema.Schema) {
	// check schema
	checkSchema(t, user, &schema.Schema{Name: "User", Table: "users"}, []string{"ID"})

	// check fields
	fields := []schema.Field{

			Fields: []schema.IndexOption{{
				Field: &schema.Field{Name: "Data1A"},
			}, {
				Field: &schema.Field{Name: "Data1B"},
			}, {
				Field: &schema.Field{Name: "Data1C"},
			}},
		},
		{
			Name:  "idx_user_indices_comp_id2",
			Class: "UNIQUE",
			Fields: []schema.IndexOption{{
				Field: &schema.Field{Name: "Data2C"},
			}, {
				Field: &schema.Field{Name: "Data2A"},
			}, {