Added documentation comments forewarning of possible API changes

Author: rwpenney

lib/matplotlib/colors.py

@@ -1691,6 +1691,11 @@ class AsinhNorm(Normalize):
     these linear and logarithmic regions is smooth, which may reduce
     the risk of visual artifacts.
 
+    .. note::
+
+       This API is provisional and may be revised in the future
+       based on early user feedback.
+
     Parameters
     ----------
     linear_width : float, default: 1

lib/matplotlib/scale.py

@@ -508,6 +508,11 @@ class AsinhScale(ScaleBase):
     :math:`a \\rightarrow a + {\\cal O}(a^3)`.
     For large values of :math:`a` the transformation behaves as
     :math:`a \\rightarrow a_0 \\, {\\rm sgn}(a) \\ln |a| + {\\cal O}(1)`.
+
+    .. note::
+
+       This API is provisional and may be revised in the future
+       based on early user feedback.
     """
 
     name = 'asinh'

lib/matplotlib/ticker.py

@@ -2613,6 +2613,11 @@ class AsinhLocator(Locator):
 
     This is very unlikely to have any use beyond
     the `~.scale.AsinhScale` class.
+
+    .. note::
+
+       This API is provisional and may be revised in the future
+       based on early user feedback.
     """
     def __init__(self, linear_width, numticks=11, symthresh=0.2,
                  base=10, subs=None):