How do I make a blank AnimationCurve for weighting random values?

According to this, I can make a weighted random value with an AnimationCurve. However, this doesn’t tell me how to make the AnimationCurve. How do I create a blank AnimationCurve?

Declare a variable of rype AnimationCurve at the rop of your class script…

public AnimationCurve animationCurve;