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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 get_block_by_hash(self, block_hash: Hash32) -> BaseBlock: """ Returns the requested block as specified by block hash. """

        validate_word(block_hash, title="Block Hash")
        block_header = self.get_block_header_by_hash(block_hash)
        return self.get_block_by_header(block_header)