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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):
 """ Actual validation. """

        try:
            self._resolve_workspace()
            if 'mets_unique_identifier' not in self.skip:
                self._validate_mets_unique_identifier()
            if 'mets_file_group_names' not in self.skip:
                self._validate_mets_file_group_names()
            if 'mets_files' not in self.skip:
                self._validate_mets_files()
            if 'pixel_density' not in self.skip:
                self._validate_pixel_density()
            if 'page' not in self.skip:
                self._validate_page()
        except Exception as e: # pylint: disable=broad-except
            self.report.add_error("Failed to instantiate workspace: %s" % e)
            #  raise e
        return self.report