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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 Definition(self):
 """Return a string with the definition of this field."""

    result = self._FormatDescriptionComment()

    result += "  enum %s {\n" % self.enum_name
    for k, v in sorted(iteritems(self.reverse_enum)):
      result += "    %s = %s;\n" % (v, k)

    result += "  }\n"

    result += self._FormatField()
    return result