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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_value(self, value):
 """Validate provided record is a part of the appropriate target app for the field"""

        if value not in (None, self._unset):

            super(ReferenceField, self).validate_value(value)

            if value.app != self.target_app:
                raise ValidationError(
                    self.record,
                    "Reference field '{}' has target app '{}', cannot reference record '{}' from app '{}'".format(
                        self.name,
                        self.target_app,
                        value,
                        value.app
                    )
                )