Combine duplicate London header fields

Author: carver

eth/vm/forks/london/blocks.py

@@ -59,42 +59,30 @@
     LondonTransactionBuilder,
 )
 
+UNMINED_LONDON_HEADER_FIELDS = [
+    ('parent_hash', hash32),
+    ('uncles_hash', hash32),
+    ('coinbase', address),
+    ('state_root', trie_root),
+    ('transaction_root', trie_root),
+    ('receipt_root', trie_root),
+    ('bloom', uint256),
+    ('difficulty', big_endian_int),
+    ('block_number', big_endian_int),
+    ('gas_limit', big_endian_int),
+    ('gas_used', big_endian_int),
+    ('timestamp', big_endian_int),
+    ('extra_data', binary),
+    ('base_fee_per_gas', big_endian_int),
+]
+
 
 class LondonMiningHeader(rlp.Serializable, MiningHeaderAPI):
-    fields = [
-        ('parent_hash', hash32),
-        ('uncles_hash', hash32),
-        ('coinbase', address),
-        ('state_root', trie_root),
-        ('transaction_root', trie_root),
-        ('receipt_root', trie_root),
-        ('bloom', uint256),
-        ('difficulty', big_endian_int),
-        ('block_number', big_endian_int),
-        ('gas_limit', big_endian_int),
-        ('gas_used', big_endian_int),
-        ('timestamp', big_endian_int),
-        ('extra_data', binary),
-        ('base_fee_per_gas', big_endian_int),
-    ]
+    fields = UNMINED_LONDON_HEADER_FIELDS
 
 
 class LondonBlockHeader(rlp.Serializable, BlockHeaderAPI):
-    fields = [
-        ('parent_hash', hash32),
-        ('uncles_hash', hash32),
-        ('coinbase', address),
-        ('state_root', trie_root),
-        ('transaction_root', trie_root),
-        ('receipt_root', trie_root),
-        ('bloom', uint256),
-        ('difficulty', big_endian_int),
-        ('block_number', big_endian_int),
-        ('gas_limit', big_endian_int),
-        ('gas_used', big_endian_int),
-        ('timestamp', big_endian_int),
-        ('extra_data', binary),
-        ('base_fee_per_gas', big_endian_int),
+    fields = UNMINED_LONDON_HEADER_FIELDS + [
         ('mix_hash', binary),
         ('nonce', Binary(8, allow_empty=True)),
     ]