Improve logging and documentation; also, SegmentedClient.getAsync() will always return a list.
diff --git a/src/main/java/com/intel/jndn/utils/FutureData.java b/src/main/java/com/intel/jndn/utils/FutureData.java
index 52ee2c2..0b4e24d 100644
--- a/src/main/java/com/intel/jndn/utils/FutureData.java
+++ b/src/main/java/com/intel/jndn/utils/FutureData.java
@@ -179,7 +179,7 @@
     }
     // case: error
     if (error != null) {
-      throw new ExecutionException("Future rejected.", error);
+      throw new ExecutionException("Future rejected with error.", error);
     }
     // case: packet
     return data;