char padChar = paddingChar.charValue();
      int l;
      for (l = chars.length() - 1; l >= 0; l--) {
        if (chars.charAt(l) != padChar) {
          break;
        }
      }
      return chars.subSequence(0, l + 1);
    }

    @Override
    public boolean canDecode(CharSequence chars) {
      checkNotNull(chars);
      chars = trimTrailingPadding(chars);

			// and restart when. If this handler reacts only to
			// changes in Spec then we have a scenario in which the
			// rollout leaves the old Status in place. The scenario
			// ends with this subsequence: deploy the last new server
			// before deleting the last old server, and in between
			// those two operations the last old server crashes and
			// recovers. The chosen solution is making this controller

// (outside compiled) computation into two separate control flow ops with
// communication between the device/host for data dependencies.  Both device and
// host control flow initially remain within `device_cluster` and a subsequency
// call to MoveToHostSingleCluster moves the host side control flow to the host
// launch in tf_device.parallel_execute.  Uses `compilation_key,
// `device_ordinal` and `communication_key_index` when creating communication