def []=(name, value)
      raise Error, "cannot set value for a Model" if @elements[name].is_a? Model
      @elements[name].value = value
    end
def []=(name, value)
      raise Error, "cannot set value for a Model" if @elements[name].is_a? Model
      @elements[name].value = value
    end
Set value of element +name+. Element should be a {Base}.
 @param [String,Symbol] name
 @param [Object] value
 @return [Object] value