message: Update GraphProperties comments
diff: @@ -29,9 +29,12 @@ namespace grappler {
  class SymbolicShapeRefiner;
  class TopoQueue;
  -// A TensorFlow model to optimize.
  -// Models are represented by the combination of a graph, one of more fetch
  -// nodes, and potentially a set of nodes to feed.
  +// Infer OpInfo::TensorProperties for graph nodes inputs/outputs.
  +//
  +// Typical use case, is to infer tensor properties from a graph, before doing
  +// optimization pass. Nodes modified during optimization pass have to be
  +// invalidated, to prevent further incorrect optimizations based on wrong shape
  +// and data type properties.
  class GraphProperties {
  public:
  explicit GraphProperties(const GrapplerItem& item) : item_(item) {}
  @@ -64,6 +67,9 @@ class GraphProperties {
  const string& node_name) const;
  const std::vector<OpInfo::TensorProperties>& GetOutputProperties(
  const string& node_name) const;
  + // Invalidate input/output properties for nodes modified during graph
  + // optimization pass, to prevent potential optimizations, based on incorrect
  + // shape information.
  void ClearInputProperties(const string& node_name);
  void ClearOutputProperties(const string& node_name);
  