From df251def26671e469d61baf4133a5d76906987a5 Mon Sep 17 00:00:00 2001
From: Lex Berezhny <lex@damoti.com>
Date: Thu, 16 Aug 2018 00:56:46 -0400
Subject: [PATCH] pylint and mypy fixes

---
 setup.cfg                   |  3 ++-
 torba/baseheader.py         |  7 ++++---
 torba/baseledger.py         |  2 +-
 torba/coin/bitcoincash.py   |  7 ++-----
 torba/coin/bitcoinsegwit.py |  3 ++-
 torba/util.py               | 10 +++++-----
 6 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/setup.cfg b/setup.cfg
index 66c7c22cf..1cb422611 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -27,4 +27,5 @@ disable=
   too-many-arguments,
   too-many-public-methods,
   too-many-instance-attributes,
-  protected-access
+  protected-access,
+  unused-argument
diff --git a/torba/baseheader.py b/torba/baseheader.py
index 04ca677df..442407c84 100644
--- a/torba/baseheader.py
+++ b/torba/baseheader.py
@@ -27,7 +27,7 @@ class BaseHeaders:
     chunk_size: int
 
     max_target: int
-    genesis_hash: bytes
+    genesis_hash: Optional[bytes]
     target_timespan: int
 
     validate_difficulty: bool = True
@@ -36,7 +36,7 @@ class BaseHeaders:
         if path == ':memory:':
             self.io = BytesIO()
         self.path = path
-        self._size = None
+        self._size: Optional[int] = None
         self._on_change_controller = StreamController()
         self.on_changed = self._on_change_controller.stream
         self._header_connect_lock = defer.DeferredLock()
@@ -61,7 +61,8 @@ class BaseHeaders:
     def get_next_chunk_target(self, chunk: int) -> ArithUint256:
         return ArithUint256(self.max_target)
 
-    def get_next_block_target(self, chunk_target: ArithUint256, previous: Optional[dict],
+    @staticmethod
+    def get_next_block_target(chunk_target: ArithUint256, previous: Optional[dict],
                               current: Optional[dict]) -> ArithUint256:
         return chunk_target
 
diff --git a/torba/baseledger.py b/torba/baseledger.py
index 24c7ad295..bde70f59c 100644
--- a/torba/baseledger.py
+++ b/torba/baseledger.py
@@ -11,7 +11,7 @@ from torba import baseaccount
 from torba import basenetwork
 from torba import basetransaction
 from torba.basedatabase import BaseDatabase
-from torba.baseheader import BaseHeaders, InvalidHeader
+from torba.baseheader import BaseHeaders
 from torba.coinselection import CoinSelector
 from torba.constants import COIN, NULL_HASH32
 from torba.stream import StreamController
diff --git a/torba/coin/bitcoincash.py b/torba/coin/bitcoincash.py
index 6678af616..77e991217 100644
--- a/torba/coin/bitcoincash.py
+++ b/torba/coin/bitcoincash.py
@@ -8,8 +8,8 @@ __electrumx__ = 'electrumx.lib.coins.BitcoinCashRegtest'
 
 from binascii import unhexlify
 from torba.baseledger import BaseLedger
-from torba.baseheader import BaseHeaders
 from torba.basetransaction import BaseTransaction
+from .bitcoinsegwit import MainHeaders, UnverifiedHeaders
 
 
 class Transaction(BaseTransaction):
@@ -23,6 +23,7 @@ class MainNetLedger(BaseLedger):
     symbol = 'BCH'
     network_name = 'mainnet'
 
+    headers_class = MainHeaders
     transaction_class = Transaction
 
     pubkey_address_prefix = bytes((0,))
@@ -33,10 +34,6 @@ class MainNetLedger(BaseLedger):
     default_fee_per_byte = 50
 
 
-class UnverifiedHeaders(BaseHeaders):
-    verify_bits_to_target = False
-
-
 class RegTestLedger(MainNetLedger):
     headers_class = UnverifiedHeaders
     network_name = 'regtest'
diff --git a/torba/coin/bitcoinsegwit.py b/torba/coin/bitcoinsegwit.py
index 89109de99..bae056eb3 100644
--- a/torba/coin/bitcoinsegwit.py
+++ b/torba/coin/bitcoinsegwit.py
@@ -7,6 +7,7 @@ __node_url__ = (
 __electrumx__ = 'electrumx.lib.coins.BitcoinSegwitRegtest'
 
 import struct
+from typing import Optional
 from binascii import hexlify, unhexlify
 from torba.baseledger import BaseLedger
 from torba.baseheader import BaseHeaders, ArithUint256
@@ -16,7 +17,7 @@ class MainHeaders(BaseHeaders):
     header_size = 80
     chunk_size = 2016
     max_target = 0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff
-    genesis_hash = b'000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'
+    genesis_hash: Optional[bytes] = b'000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'
     target_timespan = 14 * 24 * 60 * 60
 
     @staticmethod
diff --git a/torba/util.py b/torba/util.py
index 5a61d550f..8ae838027 100644
--- a/torba/util.py
+++ b/torba/util.py
@@ -1,5 +1,5 @@
 from binascii import unhexlify, hexlify
-from typing import TypeVar, Sequence
+from typing import TypeVar, Sequence, Optional
 
 
 T = TypeVar('T')
@@ -52,7 +52,7 @@ class ArithUint256:
 
     def __init__(self, value: int) -> None:
         self._value = value
-        self._compact = None
+        self._compact: Optional[int] = None
 
     @classmethod
     def from_compact(cls, compact) -> 'ArithUint256':
@@ -80,10 +80,10 @@ class ArithUint256:
     @property
     def bits(self) -> int:
         """ Returns the position of the highest bit set plus one. """
-        bn = bin(self._value)[2:]
-        for i, d in enumerate(bn):
+        bits = bin(self._value)[2:]
+        for i, d in enumerate(bits):
             if d:
-                return (len(bn) - i) + 1
+                return (len(bits) - i) + 1
         return 0
 
     @property