Diffraction_object deprecation warning

Author: bobleesj

src/diffpy/utils/scattering_objects/diffraction_objects.py

@@ -1,6 +1,6 @@
 import datetime
 from copy import deepcopy
-
+import warnings
 import numpy as np
 
 from diffpy.utils.tools import get_package_info
@@ -18,6 +18,18 @@
 
 
 class Diffraction_object:
+    """FIXME: Add class docstring.
+
+    .. deprecated:: 3.5.1
+        `Diffraction_object` will be removed in diffpy.utils 3.6.0, it is replaced by
+        `DiffractionObject` to follow the class naming convention.
+    """
+    warnings.warn(
+        "Diffraction_object` will be removed in diffpy.utils 3.6.0, it is replaced by "
+        "DiffractionObject` to follow the class naming convention.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     def __init__(self, name="", wavelength=None):
         self.name = name
         self.wavelength = wavelength