Adding a test and formatting QSD. Additionally, I make TreeScan exten…

…d ScanningGate to signify that it is an extension of the same function.

bqskit/passes/processing/treescan.py

@@ -5,20 +5,20 @@
 from typing import Any
 from typing import Callable
 
-from bqskit.compiler.basepass import BasePass
 from bqskit.compiler.passdata import PassData
 from bqskit.ir.circuit import Circuit
 from bqskit.ir.operation import Operation
 from bqskit.ir.opt.cost.functions import HilbertSchmidtResidualsGenerator
 from bqskit.ir.opt.cost.generator import CostFunctionGenerator
+from bqskit.passes.processing.scan import ScanningGateRemovalPass
 from bqskit.runtime import get_runtime
 from bqskit.utils.typing import is_integer
 from bqskit.utils.typing import is_real_number
 
 _logger = logging.getLogger(__name__)
 
 
-class TreeScanningGateRemovalPass(BasePass):
+class TreeScanningGateRemovalPass(ScanningGateRemovalPass):
     """
     The TreeScanningGateRemovalPass class.