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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 save_to_file(self, filename_prefix):
 """Save the vocabulary to a file."""

    # Wrap in single quotes to make it easier to see the full subword when
    # it has spaces and make it easier to search with ctrl+f.
    filename = self._filename(filename_prefix)
    lines = ["'%s'" % s for s in self._subwords]
    self._write_lines_to_file(filename, lines)