Tests: make prioritise_transaction.py more robust

qa/rpc-tests/test_framework/util.py

@@ -448,6 +448,8 @@ def assert_is_hash_string(string, length=64):
 def satoshi_round(amount):
     return  Decimal(amount).quantize(Decimal('0.00000001'), rounding=ROUND_DOWN)
 
+# Helper to create at least "count" utxos
+# Pass in a fee that is sufficient for relay and mining new transactions.
 def create_confirmed_utxos(fee, node, count):
     node.generate(int(0.5*count)+101)
     utxos = node.listunspent()
@@ -475,6 +477,8 @@ def create_confirmed_utxos(fee, node, count):
     assert(len(utxos) >= count)
     return utxos
 
+# Create large OP_RETURN txouts that can be appended to a transaction
+# to make it large (helper for constructing large transactions).
 def gen_return_txouts():
     # Some pre-processing to create a bunch of OP_RETURN txouts to insert into transactions we create
     # So we have big transactions (and therefore can't fit very many into each block)
@@ -501,6 +505,8 @@ def create_tx(node, coinbase, to_address, amount):
     assert_equal(signresult["complete"], True)
     return signresult["hex"]
 
+# Create a spend of each passed-in utxo, splicing in "txouts" to each raw
+# transaction to make it large.  See gen_return_txouts() above.
 def create_lots_of_big_transactions(node, txouts, utxos, fee):
     addr = node.getnewaddress()
     txids = []