attach contextual information to it (for instance, which
    parameter it is).

    .. versionadded:: 2.0

    :param param: the parameter object that caused this error.  This can
                  be left out, and Click will attach this info itself
                  if possible.
    :param param_hint: a string that shows up as parameter name.  This
                       can be used as alternative to `param` in cases
                       where custom validation should happen.  If it is
                       a string it's used as such, if it's a list then
                       each item is quoted and separated.
    Nc