--- a/src/SbpOperators/stencil.jl	Fri Apr 12 10:11:52 2024 +0200
+++ b/src/SbpOperators/stencil.jl	Fri Apr 12 12:26:30 2024 +0200
@@ -80,6 +80,18 @@
     end
 end
 
+# There are many options for the implementation of `apply_stencil` and
+# `apply_stencil_backwards`. Some alternatives were tried on the branch
+# bugfix/sbp_operators/stencil_return_type and can be found at the following
+# revision:
+#
+# * 237b980ffb91 (baseline)
+# * a72bab15228e (mapreduce)
+# * ffd735354d54 (multiplication)
+# * b5abd5191f2c (promote_op)
+# * 8d56846185fc (return_type)
+#
+
 function left_pad(s::Stencil, N)
     weights = LazyTensors.left_pad_tuple(s.weights, zero(eltype(s)), N)
     range = (first(s.range) - (N - length(s.weights))):last(s.range)