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diff --git a/src/python/_framework/base/util.py b/src/python/_framework/base/util.py
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+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Utilities helpful for working with the base layer of RPC Framework."""
+
+import collections
+import threading
+
+from _framework.base import interfaces
+
+
+class _ServicedSubscription(
+    collections.namedtuple('_ServicedSubscription', ['category', 'ingestor']),
+    interfaces.ServicedSubscription):
+  """See interfaces.ServicedSubscription for specification."""
+
+_NONE_SUBSCRIPTION = _ServicedSubscription(interfaces.NONE, None)
+_TERMINATION_ONLY_SUBSCRIPTION = _ServicedSubscription(
+    interfaces.TERMINATION_ONLY, None)
+
+
+def none_serviced_subscription():
+  """Creates a "none" interfaces.ServicedSubscription object.
+
+  Returns:
+    An interfaces.ServicedSubscription indicating no subscription to an
+      operation's results (such as would be the case for a fire-and-forget
+      operation invocation).
+  """
+  return _NONE_SUBSCRIPTION
+
+
+def termination_only_serviced_subscription():
+  """Creates a "termination only" interfaces.ServicedSubscription object.
+
+  Returns:
+    An interfaces.ServicedSubscription indicating that the front-side customer
+      is interested only in the overall termination outcome of the operation
+      (such as completion or expiration) and would ignore the actual results of
+      the operation.
+  """
+  return _TERMINATION_ONLY_SUBSCRIPTION
+
+
+def full_serviced_subscription(ingestor):
+  """Creates a "full" interfaces.ServicedSubscription object.
+
+  Args:
+    ingestor: A ServicedIngestor.
+
+  Returns:
+    A ServicedSubscription object indicating a full subscription.
+  """
+  return _ServicedSubscription(interfaces.FULL, ingestor)
+
+
+def wait_for_idle(end):
+  """Waits for an interfaces.End to complete all operations.
+
+  Args:
+    end: Any interfaces.End.
+  """
+  event = threading.Event()
+  end.add_idle_action(event.set)
+  event.wait()