How to use the pyscreeze.__init__.PyScreezeException function in PyScreeze

def wrapper(*args, **kwargs):
        if _PILLOW_UNAVAILABLE:
            raise PyScreezeException('The Pillow package is required to use this function.')
        return wrappedFunction(*args, **kwargs)
    return wrapper

if hDC == 0: #NULL
            raise WindowsError("windll.user32.GetDC failed : return NULL")
        try:
            yield hDC
        finally:
            if windll.user32.ReleaseDC(hWnd, hDC) == 0:
                raise WindowsError("windll.user32.ReleaseDC failed : return 0")

Box = collections.namedtuple('Box', 'left top width height')
Point = collections.namedtuple('Point', 'x y')
RGB = collections.namedtuple('RGB', 'red green blue')

class PyScreezeException(Exception):
    pass # This is a generic exception class raised when a PyScreeze-related error happens.

class ImageNotFoundException(PyScreezeException):
    pass # This is an exception class raised when the locate functions fail to locate an image.


def requiresPillow(wrappedFunction):
    """
    A decorator that marks a function as requiring Pillow to be installed.
    This raises PyScreezeException if Pillow wasn't imported.
    """
    @functools.wraps(wrappedFunction)
    def wrapper(*args, **kwargs):
        if _PILLOW_UNAVAILABLE:
            raise PyScreezeException('The Pillow package is required to use this function.')
        return wrappedFunction(*args, **kwargs)
    return wrapper

def _load_cv2(img, grayscale=None):