Adding "speed" parameter breaks animation

[kurealnum]

Adding the speed parameter to the Starback class init breaks the animation. The background still displays properly, but no stars are displayed. Take a look at this Codepen for example.

[VladChernyak]

The documentation specifies the type of the expected parameter incorrectly. You need to pass not a number, but an array with several values, for example:

{
  ...
  speed: [0.2, 0.4],
}