'Convert ``element`` to ``self.dtype`` given the base domain.'

def convert_from(self, element, base):

    if (base.alias is not None):
        method = ('from_' + base.alias)
    else:
        method = ('from_' + base.__class__.__name__)
    _convert = getattr(self, method)
    if (_convert is not None):
        result = _convert(element, base)
        if (result is not None):
            return result
    raise CoercionFailed(("can't    convert    %s    of    type    %s    from    %s    to    %s" % (element, type(element), base, self)))
