Fix warning.

torch_spline_conv/conv.py

@@ -7,7 +7,7 @@ from .utils.degree import degree as node_degree
 
 
 class SplineConv(object):
-    """Applies the spline-based convolution operator :math:`(f \star g)(i) =
+    r"""Applies the spline-based convolution operator :math:`(f \star g)(i) =
     \frac{1}{|\mathcal{N}(i)|} \sum_{l=1}^{M_{in}} \sum_{j \in \mathcal{N}(i)}
     f_l(j) \cdot g_l(u(i, j))` over several node features of an input graph.
     The kernel function :math:`g_l` is defined over the weighted B-spline