def test_block_dupe_tx(self, b, alice):
from bigchaindb.models import Block, Transaction
from bigchaindb.common.exceptions import DuplicateTransaction
tx = Transaction.create([alice.public_key], [([alice.public_key], 1)])
block = Block([tx, tx], alice.public_key)
block.sign(alice.private_key)
b.store_block(block.to_dict())
with raises(DuplicateTransaction):
block.validate(b)
