code: function getDefaultValue(entity) {
    expect(arguments).to.have.length(
      1,
      'Invalid arguments length when getting the default value of an Attribute ' +
      'to an Entity instance (it has to be given 1 argument)'
    );
  
    expect(entity).to.be.an.instanceOf(
      models.Entity,
      'Invalid type of argument "entity" when getting the default value of an ' +
      'Attribute to an Entity instance (it has to be an Entity)'
    );
  
    if (typeof this.default === 'function') {
      return this.default.call(entity);
    } else {
      return this.default;
    }
  }
docs: Gets the default value of the current Attribute to a given Entity instance.
  @name module:back4app-entity/models/attributes.Attribute#getDefaultValue
  @function
  @param {!module:back4app-entity/models.Entity} entity The Entity instance to
  which the default value will be get.
  @returns {boolean|number|string|Object|function} The default value.
  @example
  var defaultValue = MyEntity.attributes.myAttribute.getDefaultValue(
  new MyEntity()
  );