NgFormControl(@ @ @ List _validators, @ @ @ List _asyncValidators, @ @ @ List<ControlValueAccessor> valueAccessors)

Source 

NgFormControl(
    @Optional()
    @Self()
    @Inject(NG_VALIDATORS)
        this._validators,
    @Optional()
    @Self()
    @Inject(NG_ASYNC_VALIDATORS)
        this._asyncValidators,
    @Optional()
    @Self()
    @Inject(NG_VALUE_ACCESSOR)
        List<ControlValueAccessor> valueAccessors) {
  this.valueAccessor = selectValueAccessor(this, valueAccessors);
}