def valid?
      return false if @sync.nil?
      sync_validator = EnumAttributeValidator.new('String', ["true", "false"])
      return false unless sync_validator.valid?(@sync)
      return true
    end
def valid?
      return false if @sync.nil?
      sync_validator = EnumAttributeValidator.new('String', ["true", "false"])
      return false unless sync_validator.valid?(@sync)
      return true
    end
Check to see if the all the properties in the model are valid
 @return true if the model is valid