Error: "Undefined reference to..." using MLX90614 Example Code

I was unable to compile Sparkfun MLX90614 example code "MLX90614_Get_ID.ino"

The MLX90614.h file is located in the libraries folder and included using an #include <MLX90614.h> statement.

When I do compile, I get multiple error instances of "Undefined reference to 'IRTherm :: begin(unsigned char)" or other instances of the IRTherm object/class being an undefined reference.

The code is below.

#include <Wire.h> // I2C library, required for MLX90614
#include <SparkFunMLX90614.h> // SparkFunMLX90614 Arduino library

IRTherm therm; // Create an IRTherm object to interact with throughout

void setup() 
{
  Serial.begin(9600); // Initialize Serial to log output
  therm.begin(); // Initialize the MLX90614
  
  if (therm.readID()) // Read from the ID registers
  { // If the read succeeded, print the ID:
    Serial.println("ID: 0x" + 
                   String(therm.getIDH(), HEX) +
                   String(therm.getIDL(), HEX));
  }
}

void loop() 
{

}

The MLX90614.h file is located in the libraries folder

Is the .cpp file also there?