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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 __create_document_header(self):
 """ Look, mum! XML generation without string concatenation!1!! This creates an empty, but functional header for an Exmaralda *.exb file. """

        E = self.E
        root = E('basic-transcription')
        head = E('head')

        meta = E('meta-information')
        project = E('project-name')
        tname = E('transcription-name')
        ref_file = E('referenced-file', url="")
        ud = E('ud-meta-information')
        comment = E('comment')
        tconvention = E('transcription-convention')
        meta.append(project)
        meta.append(tname)
        meta.append(ref_file)
        meta.append(ud)
        meta.append(comment)
        meta.append(tconvention)

        speakers = E('speakertable')
        head.append(meta)
        head.append(speakers)
        root.append(head)
        return root