How to utilize ADC Noise Reduction mode?

[azirger2]

Within the ATTinyCore Arduino environment, how do I go about doing an ADC conversion with the Noise Reduction mode enabled? I'm using a Digispark Pro board.

I see a reference in the Arduino.h file of:
#ifdef SLEEP_MODE_ADC
int analogRead_NR(uint8_t pin);
int _analogRead(uint8_t pin, bool use_noise_reduction);
#else
int _analogRead(uint8_t pin);
#endif

so, I think the capability is supported.

Thanks.

[azirger2]

I should also say, in the README.md file, it says to just use analogRead_NR() instead of analogRead(), but when I do, I get the message:
Compilation error: 'analogRead_NR' was not declared in this scope

[azirger2]

I'm using the installed 1.5.2 ATTinyCore library and I see the Arduino.h is not the same as the one if I'm perusing the GitHub path to:
ATTinyCore/avr/cores/tiny/Arduino.h

The installed Arduino.h I'm thinking is what my system is using down in:
...\ATTinyCore-1.5.2\ATTinyCore-1.5.2\avr\cores\tiny

has no mention of the analogRead_NR() function.

I guess that returns to my original question: How do I set up my system to be able to use the analogRead_NR() capability for a Digispark Pro in the current Arduino environment (I'm running Arduino IDE 2.3.3)?