def __init__(self, caption, height, width):
self.caption = caption<EOL>self.height = height<EOL>self.width = width<EOL>self._window = None<EOL>
Initialize a new image viewer.

Args:
    caption (str): the caption/title for the window
    height (int): the height of the window
    width (int): the width of the window

Returns:
    None