def keyDown(key, pause=None, _pause=True):
    """Performs a keyboard key press without the release. This will put that
    key in a held down state.

    NOTE: For some reason, this does not seem to cause key repeats like would
    happen if a keyboard key was held down on a text field.

    Args:
      key (str): The key to be pressed down. The valid names are listed in
      KEYBOARD_KEYS.

    Returns:
      None
    """
    if len(key) > 1:
        key = key.lower()

    _failSafeCheck()
    platformModule._keyDown(key)

    _autoPause(pause, _pause)