diff --git a/graphql/__init__.py b/graphql/__init__.py
index 20f5c995..434b5a75 100644
--- a/graphql/__init__.py
+++ b/graphql/__init__.py
@@ -205,7 +205,7 @@
     set_default_backend,
 )
 
-VERSION = (2, 1, 0, 'rc', 1)
+VERSION = (2, 1, 0, 'rc', 2)
 __version__ = get_version(VERSION)
 
 
diff --git a/graphql/backend/quiver_cloud.py b/graphql/backend/quiver_cloud.py
index f760c5fc..d8ac8233 100644
--- a/graphql/backend/quiver_cloud.py
+++ b/graphql/backend/quiver_cloud.py
@@ -6,12 +6,12 @@
         "You can install it using: pip install requests"
     )
 
-from six import urlparse
-
 from ..utils.schema_printer import print_schema
 from .base import GraphQLBackend
 from .compiled import GraphQLCompiledDocument
 
+from six.moves.urllib.parse import urlparse
+
 
 GRAPHQL_QUERY = """
 mutation($schemaDsl: String!, $query: String!) {
diff --git a/graphql/execution/base.py b/graphql/execution/base.py
index 55c32e54..a209dc8b 100644
--- a/graphql/execution/base.py
+++ b/graphql/execution/base.py
@@ -1,9 +1,16 @@
 # We keep the following imports to preserve compatibility
-from .utils import (ExecutionContext, SubscriberExecutionContext,
-                    collect_fields, default_resolve_fn,
-                    does_fragment_condition_match, get_field_def,
-                    get_field_entry_key, get_operation_root_type,
-                    should_include_node)
+from .utils import (
+    ExecutionContext,
+    SubscriberExecutionContext,
+    get_operation_root_type,
+    collect_fields,
+    should_include_node,
+    does_fragment_condition_match,
+    get_field_entry_key,
+    default_resolve_fn,
+    get_field_def
+)
+from ..error.format_error import format_error as default_format_error
 
 
 class ExecutionResult(object):
@@ -33,6 +40,19 @@ def __eq__(self, other):
             )
         )
 
+    def to_dict(self, format_error=None, dict_class=dict):
+        if format_error is None:
+            format_error = default_format_error
+
+        response = dict_class()
+        if self.errors:
+            response['errors'] = [format_error(e) for e in self.errors]
+
+        if not self.invalid:
+            response['data'] = self.data
+
+        return response
+
 
 class ResolveInfo(object):
     __slots__ = ('field_name', 'field_asts', 'return_type', 'parent_type',
diff --git a/graphql/execution/executors/asyncio.py b/graphql/execution/executors/asyncio.py
index 541e6cf6..13f19028 100644
--- a/graphql/execution/executors/asyncio.py
+++ b/graphql/execution/executors/asyncio.py
@@ -62,5 +62,5 @@ def execute(self, fn, *args, **kwargs):
             self.futures.append(future)
             return Promise.resolve(future)
         elif isasyncgen(result):
-            return asyncgen_to_observable(result)
+            return asyncgen_to_observable(result, loop=self.loop)
         return result
diff --git a/graphql/execution/executors/asyncio_utils.py b/graphql/execution/executors/asyncio_utils.py
index d5e0464c..b327cec6 100644
--- a/graphql/execution/executors/asyncio_utils.py
+++ b/graphql/execution/executors/asyncio_utils.py
@@ -1,4 +1,4 @@
-from asyncio import ensure_future
+from asyncio import ensure_future, wait, CancelledError
 from inspect import isasyncgen
 
 from rx import AnonymousObserver, Observable
@@ -7,6 +7,7 @@
                      ObserverBase)
 from rx.core.anonymousobserver import AnonymousObserver
 from rx.core.autodetachobserver import AutoDetachObserver
+from rx import AnonymousObservable
 
 
 # class AsyncgenDisposable(Disposable):
@@ -102,27 +103,16 @@ def set_disposable(scheduler=None, value=None):
             else:
                 auto_detach_observer.disposable = fix_subscriber(subscriber)
 
-        # Subscribe needs to set up the trampoline before for subscribing.
-        # Actually, the first call to Subscribe creates the trampoline so
-        # that it may assign its disposable before any observer executes
-        # OnNext over the CurrentThreadScheduler. This enables single-
-        # threaded cancellation
-        # https://social.msdn.microsoft.com/Forums/en-US/eb82f593-9684-4e27-
-        # 97b9-8b8886da5c33/whats-the-rationale-behind-how-currentthreadsche
-        # dulerschedulerequired-behaves?forum=rx
-        if current_thread_scheduler.schedule_required():
-            current_thread_scheduler.schedule(set_disposable)
-        else:
-            set_disposable()
+        def dispose():
+            async def await_task():
+                await task
 
-        # Hide the identity of the auto detach observer
-        return Disposable.create(auto_detach_observer.dispose)
+            task.cancel()
+            ensure_future(await_task(), loop=loop)
 
+        return dispose
 
-def asyncgen_to_observable(asyncgen):
-    def emit(observer):
-        ensure_future(iterate_asyncgen(asyncgen, observer))
-    return AsyncgenObservable(emit, asyncgen)
+    return AnonymousObservable(emit)
 
 
 async def iterate_asyncgen(asyncgen, observer):
@@ -130,5 +120,7 @@ async def iterate_asyncgen(asyncgen, observer):
         async for item in asyncgen:
             observer.on_next(item)
         observer.on_completed()
+    except CancelledError:
+        pass
     except Exception as e:
         observer.on_error(e)
diff --git a/graphql/execution/middleware.py b/graphql/execution/middleware.py
index 7a0ad386..ce81da47 100644
--- a/graphql/execution/middleware.py
+++ b/graphql/execution/middleware.py
@@ -10,9 +10,9 @@
 class MiddlewareManager(object):
     __slots__ = "middlewares", "wrap_in_promise", "_middleware_resolvers", "_cached_resolvers"
 
-    def __init__(self, *middlewares, wrap_in_promise=True):
+    def __init__(self, *middlewares, **kwargs):
         self.middlewares = middlewares
-        self.wrap_in_promise = wrap_in_promise
+        self.wrap_in_promise = kwargs.get('wrap_in_promise', True)
         self._middleware_resolvers = list(get_middleware_resolvers(middlewares)) if middlewares else []
         self._cached_resolvers = {}