code: def block_verify( block_data ):
      
      
      # verify block data txs 
      m = merkle.MerkleTree( block_data['tx'] )
      root_hash = str(m.root())
  
      return root_hash == str(block_data['merkleroot'])
docs: Given block data (a dict with 'merkleroot' hex string and 'tx' list of hex strings--i.e.
      a block compatible with bitcoind's getblock JSON RPC method), verify that the
      transactions are consistent.
  
      Return True on success
      Return False if not.