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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def image_format(value):
 """ Confirms that the uploaded image is of supported format. Args: value (File):
 The file with an `image` property containing the image Raises: django.forms.ValidationError """


    if value.image.format.upper() not in constants.ALLOWED_IMAGE_FORMATS:
        raise ValidationError(MESSAGE_INVALID_IMAGE_FORMAT)