class KeyboardMatrix

{
    row: Integer,
    col: Integer,
    pressed: bool
  }

KeyboardMatrix.new(Array[Integer] row_pins, ?Array[Integer] col_pins) -> KeyboardMatrix

instance.debounce_ms() -> Integer

instance.debounce_ms=(Integer ms) -> Integer

instance.scan() -> key_event?

instance.start() { (key_event) -> void } -> void