1 files changed, 29 insertions, 0 deletions
diff --git a/tensorflow/python/training/optimizer.py b/tensorflow/python/training/optimizer.py
index 9e029389f2..e862cb87b1 100644
--- a/tensorflow/python/training/optimizer.py
+++ b/tensorflow/python/training/optimizer.py
@@ -34,6 +34,8 @@ from tensorflow.python.training import slot_creator
 
 
 def _var_key(var):
+  if var.op.type == "ResourceGather":
+    var = var.op.inputs[0]
   return (var.op.graph, var.op.name)
 
 
@@ -530,6 +532,33 @@ class Optimizer(object):
     raise NotImplementedError()
 
   def _resource_apply_dense(self, grad, handle):
+    """Add ops to apply dense gradients to the variable `handle`.
+
+    Args:
+      grad: a `Tensor` representing the gradient.
+      handle: a `Tensor` of dtype `resource` which points to the variable
+       to be updated.
+
+    Returns:
+      An `Operation` which updates the value of the variable.
+    """
+    raise NotImplementedError()
+
+  def _resource_apply_sparse(self, grad, handle, indices):
+    """Add ops to apply sparse gradients to the variable `handle`.
+
+
+    Args:
+      grad: a `Tensor` representing the gradient for the affected indices.
+      handle: a `Tensor` of dtype `resource` which points to the variable
+       to be updated.
+      indices: a `Tensor` of integral type representing the indices for
+       which the gradient is nonzero.
+
+    Returns:
+      An `Operation` which updates the value of the variable.
+
+    """
     raise NotImplementedError()
 
   def _apply_sparse_duplicate_indices(self, grad, var):