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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 _resolve_workspace(self):
 """ Clone workspace from mets_url unless workspace was provided. """

        if self.workspace is None:
            self.workspace = self.resolver.workspace_from_url(self.mets_url, baseurl=self.src_dir, download=self.download)
            self.mets = self.workspace.mets