PaintLinearGradient
PaintLinearGradient class has the following properties:
begin
An instance of Offset. The offset at which stop 0.0 of the gradient is placed.
colors
The colors the gradient should obtain at each of the stops. This list must contain at least two colors.
If stops is provided, this list must have the same length as stops.
end
An instance of Offset. The offset at which stop 1.0 of the gradient is placed.