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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 as_tmpfile(self, tmpdir=None):
 """ Copy the pseudopotential to a temporary a file and returns a new pseudopotential object. Useful for unit tests in which we have to change the content of the file. Args: tmpdir: If None, a new temporary directory is created and files are copied here else tmpdir is used. """

        import tempfile, shutil
        tmpdir = tempfile.mkdtemp() if tmpdir is None else tmpdir
        new_path = os.path.join(tmpdir, self.basename)
        shutil.copy(self.filepath, new_path)

        # Copy dojoreport file if present.
        root, ext = os.path.splitext(self.filepath)
        djrepo = root + ".djrepo"
        if os.path.exists(djrepo):
            shutil.copy(djrepo, os.path.join(tmpdir, os.path.basename(djrepo)))

        # Build new object and copy dojo_report if present.
        new = self.__class__.from_file(new_path)
        if self.has_dojo_report: new.dojo_report = self.dojo_report.deepcopy()

        return new