'Get the ultimate type of a repeated validator.
Looks for an instance of validation.Repeated, returning its constructor.
Args:
attribute: Repeated validator attribute to find type for.
Returns:
The expected class of of the Type validator, otherwise object.'

def _GetRepeated(self, attribute):

    if isinstance(attribute, validation.Optional):
        attribute = attribute.validator
    if isinstance(attribute, validation.Repeated):
        return attribute.constructor
    return object
