Small doc fixes (#1319)

* Clean up grammar in paragraph about callbacks

* Structure event draining examples into subsections

* Make code example make more sense

… and bring it more in line with text above.

* Fix code example

* Fix another code example

typo in method name

docs/userguide/consumers.rst

@@ -24,7 +24,7 @@ drain events from all channels on that connection.
 
         >>> Consumer(conn, accept=['json', 'pickle', 'msgpack', 'yaml'])
 
-You can create a consumer using a Connection. Consumer is consuming from single queue with name `'queue'`:
+You can create a consumer using a Connection. This consumer is consuming from a single queue with name `'queue'`:
 
 .. code-block:: python
 
@@ -41,10 +41,10 @@ consumes from single queue with name `'queue'`:
     ...     with conn.channel() as channel:
     ...         consumer = Consumer(channel, queue)
 
-Consumer needs to specify handler of received data. This handler specified in form of callback. Callback function is called
+A consumer needs to specify a handler for received data. This handler is specified in the form of a callback. The callback function is called
-by kombu library every time a new message is received. Callback is called with two parameters ``body`` containing deserialized
+by kombu every time a new message is received. The callback is called with two parameters: ``body``, containing deserialized
-data sent by producer and :class:`~kombu.message.Message` instance ``message``. User is also responsible for acknowledging of message when manual
+data sent by a producer, and a :class:`~kombu.message.Message` instance ``message``. The user is responsible for acknowledging messages when manual
-acknowledge is set.
+acknowledgement is set.
 
 .. code-block:: python
 
@@ -54,21 +54,29 @@ acknowledge is set.
 
     >>> consumer.register_callback(callback)
 
-Draining events from a single consumer. Method ``drain_events`` by default blocks indefinitely. This example sets timeout to 1 second:
+Draining events from a single consumer
+--------------------------------------
 
+The method ``drain_events`` blocks indefinitely by default. This example sets the timeout to 1 second:
+ 
 .. code-block:: python
 
     >>> with consumer:
     ...     connection.drain_events(timeout=1)
 
-Draining events from several consumers. Each consumer has its own list of queues. Each consumer accepts `'json'` format of data:
+Draining events from several consumers
+--------------------------------------
+
+Each consumer has its own list of queues. Each consumer accepts data in `'json'` format:
 
 .. code-block:: python
 
     >>> from kombu.utils.compat import nested
 
-    >>> queues1 = [Queue('queue11', routing_key='queue12')]
+    >>> queues1 = [Queue('queue11', routing_key='queue11'),
-    >>> queues2 = [Queue('queue21', routing_key='queue22')]
+                   Queue('queue12', routing_key='queue12')]
+    >>> queues2 = [Queue('queue21', routing_key='queue21'),
+                   Queue('queue22', routing_key='queue22')]
     >>> with connection.channel(), connection.channel() as (channel1, channel2):
     ...     with nested(Consumer(channel1, queues1, accept=['json']),
     ...                 Consumer(channel2, queues2, accept=['json'])):
@@ -113,7 +121,7 @@ mixin class and overriding some of the methods:
 
         def get_consumers(self, Consumer, channel):
             return [
-                Consumer(queues, callbacks=[self.on_message], accept=['json']),
+                Consumer(channel, callbacks=[self.on_message], accept=['json']),
             ]
 
         def on_message(self, body, message):
@@ -145,7 +153,7 @@ and with multiple channels again:
                              callbacks=[self.on_special_message],
                              accept=['json'])]
 
-        def on_consumer_end(self, connection, default_channel):
+        def on_consume_end(self, connection, default_channel):
             if self.channel2:
                 self.channel2.close()