More updates

Author: odeke-em

google-cloud-spanner/src/main/java/com/google/cloud/spanner/Options.java

@@ -1093,8 +1093,6 @@ public int hashCode() {
 
     @Override
     public boolean equals(Object o) {
-      // TODO: Examine why the precedent for LastStatementUpdateOption
-      // does not check against the actual value.
       return o instanceof RequestIdOption;
     }
   }

google-cloud-spanner/src/main/java/com/google/cloud/spanner/SessionImpl.java

@@ -126,7 +126,7 @@ interface SessionTransaction {
   private final Clock clock;
   private final Map<SpannerRpc.Option, ?> options;
   private final ErrorHandler errorHandler;
-  private XGoogSpannerRequestId.RequestIdCreator requestIdCreator;
+  private final XGoogSpannerRequestId.RequestIdCreator requestIdCreator;
 
   SessionImpl(SpannerImpl spanner, SessionReference sessionReference) {
     this(spanner, sessionReference, NO_CHANNEL_HINT);