def formatHint(self):
    return 'This resource may get downloaded and cached on the client computer. To ensure up-to-date resources, append a unique ID to the URL such as a timestamp of when the resources changed on your server, e.g. https://awesomefonts.com/xyz/regular/specimen.pdf?t=1548239062. Don’t use the current time for a timestamp, as this will mean constant reloading the resource when it actually hasn’t changed. Instead use the resource’s server-side change timestamp.'
def formatHint(self):
    return 'This resource may get downloaded and cached on the client computer. To ensure up-to-date resources, append a unique ID to the URL such as a timestamp of when the resources changed on your server, e.g. https://awesomefonts.com/xyz/regular/specimen.pdf?t=1548239062. Don’t use the current time for a timestamp, as this will mean constant reloading the resource when it actually hasn’t changed. Instead use the resource’s server-side change timestamp.'