Remove unnecessary type: ignore

Author: carver

eth/tools/mining.py

@@ -1,19 +1,19 @@
+from eth.abc import (
+    BlockAPI,
+    VirtualMachineAPI,
+)
 from eth.consensus import (
     pow,
 )
 
-from eth.rlp.blocks import (
-    BaseBlock,
-)
-
 
-class POWMiningMixin:
+class POWMiningMixin(VirtualMachineAPI):
     """
     A VM that does POW mining as well. Should be used only in tests, when we
     need to programatically populate a ChainDB.
     """
-    def finalize_block(self, block: BaseBlock) -> BaseBlock:
-        block = super().finalize_block(block)  # type: ignore
+    def finalize_block(self, block: BlockAPI) -> BlockAPI:
+        block = super().finalize_block(block)
         nonce, mix_hash = pow.mine_pow_nonce(
             block.number, block.header.mining_hash, block.header.difficulty)
         return block.copy(header=block.header.copy(nonce=nonce, mix_hash=mix_hash))