Remove extraneous optional traversal argument to drive_fmm

Author: inducer

pytential/qbx/fmm.py

@@ -400,8 +400,7 @@ def make_container():
 
 # {{{ FMM top-level
 
-def drive_fmm(expansion_wrangler, src_weight_vecs, timing_data=None,
-        traversal=None):
+def drive_fmm(expansion_wrangler, src_weight_vecs, timing_data=None):
     """Top-level driver routine for the QBX fast multipole calculation.
 
     :arg geo_data: A :class:`pytential.qbx.geometry.QBXFMMGeometryData` instance.
@@ -419,10 +418,7 @@ def drive_fmm(expansion_wrangler, src_weight_vecs, timing_data=None,
     wrangler = expansion_wrangler
 
     geo_data = wrangler.geo_data
-
-    if traversal is None:
-        traversal = geo_data.traversal()
-
+    traversal = wrangler.traversal
     tree = traversal.tree
 
     template_ary = src_weight_vecs[0]

test/test_cost_model.py

@@ -745,8 +745,8 @@ def test_cost_model_correctness(actx_factory, dim, off_surface,
     src_weights = np.ones(ndofs)
 
     timing_data = {}
-    potential = drive_fmm(wrangler, (src_weights,), timing_data,
-            traversal=wrangler.trav)[0][geo_data.ncenters:]
+    potential = drive_fmm(wrangler, (src_weights,), timing_data
+            )[0][geo_data.ncenters:]
 
     # Check constant one wrangler for correctness.
     assert np.all(potential == ndofs)