How to script NumberSequences in ParticleEmitters?

I can't seem to script any type of NumberSequences for ParticleEmitters. What am I doing wrong, and could I have an example of NumberSequence use in a script?

Here is my current code:

local plr = game.Players.LocalPlayer
local chr = plr.Character

local particleEmitter = Instance.new("ParticleEmitter", chr.Torso)

local heartsSizeSequence = "0 0.2 0 0.499452 0.3125 0 1 0.2 0"
local heartsSequence = NumberSequence.new(heartsSizeSequence)

particleEmitter.Size = heartsSequence

Crunchy_Roll's method does not work for every circumstance, but it indeed does work.

Anyways, I solved it in circumstances that will work every time.

You can use an array with the values and call them in NumberSequenceKeypoint.new(time, value, envelope).

Hence:

local heartsSizeSequence = {"0", "1"}
local keypoints = {NumberSequenceKeyPoint.new(0, heartsSizeSequence[1], 0), NumberSequenceKeyPoint.new(1, heartsSizeSequence[2], 0)}

particleEmitter.Size = NumberSequence.new(keypoints)