Delete an unused private method.

anntzer · anntzer · commit a9d6d2bff167 · 2019-01-05T19:28:06.000+01:00
... since bde568c (2007).
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
@@ -1728,14 +1728,6 @@ def __array__(self, *args, **kwargs):
         # optimises the access of the transform matrix vs the superclass
         return self.get_matrix()
 
-    @staticmethod
-    def _concat(a, b):
-        """
-        Concatenates two transformation matrices (represented as numpy
-        arrays) together.
-        """
-        return np.dot(b, a)
-
     def __eq__(self, other):
         if getattr(other, "is_affine", False):
             return np.all(self.get_matrix() == other.get_matrix())
