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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 validate(self):
 """Explicitly validate all the fields."""

        for name, field in self:
            try:
                field.validate_for_object(self)
            except ValidationError as error:
                raise ValidationError(
                    "Error for field '{name}'.".format(name=name),
                    error,
                )