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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 Header(self):
 """ Get the block header. Returns: neo.Core.Header: """

        if not self._header:
            self._header = Header(self.PrevHash, self.MerkleRoot, self.Timestamp,
                                  self.Index, self.ConsensusData, self.NextConsensus, self.Script)

        return self._header