diff --git a/docs/oauth2client.client.html b/docs/oauth2client.client.html
index 431b96a..0eb8524 100644
--- a/docs/oauth2client.client.html
+++ b/docs/oauth2client.client.html
@@ -65,7 +65,8 @@
 </font></dt><dd>
 <dl>
 <dt><font face="helvetica, arial"><a href="oauth2client.client.html#AccessTokenCredentialsError">AccessTokenCredentialsError</a>
-</font></dt><dt><font face="helvetica, arial"><a href="oauth2client.client.html#RequestError">RequestError</a>
+</font></dt><dt><font face="helvetica, arial"><a href="oauth2client.client.html#AccessTokenRefreshError">AccessTokenRefreshError</a>
+</font></dt><dt><font face="helvetica, arial"><a href="oauth2client.client.html#FlowExchangeError">FlowExchangeError</a>
 </font></dt></dl>
 </dd>
 </dl>
@@ -235,6 +236,67 @@
 <table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
 <tr bgcolor="#ffc8d8">
 <td colspan=3 valign=bottom>&nbsp;<br>
+<font color="#000000" face="helvetica, arial"><a name="AccessTokenRefreshError">class <strong>AccessTokenRefreshError</strong></a>(<a href="oauth2client.client.html#Error">Error</a>)</font></td></tr>
+    
+<tr bgcolor="#ffc8d8"><td rowspan=2><tt>&nbsp;&nbsp;&nbsp;</tt></td>
+<td colspan=2><tt><a href="#Error">Error</a>&nbsp;occurred&nbsp;during&nbsp;request.<br>&nbsp;</tt></td></tr>
+<tr><td>&nbsp;</td>
+<td width="100%"><dl><dt>Method resolution order:</dt>
+<dd><a href="oauth2client.client.html#AccessTokenRefreshError">AccessTokenRefreshError</a></dd>
+<dd><a href="oauth2client.client.html#Error">Error</a></dd>
+<dd><a href="exceptions.html#Exception">exceptions.Exception</a></dd>
+<dd><a href="exceptions.html#BaseException">exceptions.BaseException</a></dd>
+<dd><a href="__builtin__.html#object">__builtin__.object</a></dd>
+</dl>
+<hr>
+Data descriptors inherited from <a href="oauth2client.client.html#Error">Error</a>:<br>
+<dl><dt><strong>__weakref__</strong></dt>
+<dd><tt>list&nbsp;of&nbsp;weak&nbsp;references&nbsp;to&nbsp;the&nbsp;object&nbsp;(if&nbsp;defined)</tt></dd>
+</dl>
+<hr>
+Methods inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
+<dl><dt><a name="AccessTokenRefreshError-__init__"><strong>__init__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__init__">__init__</a>(...)&nbsp;initializes&nbsp;x;&nbsp;see&nbsp;x.__class__.__doc__&nbsp;for&nbsp;signature</tt></dd></dl>
+
+<hr>
+Data and other attributes inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
+<dl><dt><strong>__new__</strong> = &lt;built-in method __new__ of type object&gt;<dd><tt>T.<a href="#AccessTokenRefreshError-__new__">__new__</a>(S,&nbsp;...)&nbsp;-&gt;&nbsp;a&nbsp;new&nbsp;<a href="__builtin__.html#object">object</a>&nbsp;with&nbsp;type&nbsp;S,&nbsp;a&nbsp;subtype&nbsp;of&nbsp;T</tt></dl>
+
+<hr>
+Methods inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:<br>
+<dl><dt><a name="AccessTokenRefreshError-__delattr__"><strong>__delattr__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__delattr__">__delattr__</a>('name')&nbsp;&lt;==&gt;&nbsp;del&nbsp;x.name</tt></dd></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__getattribute__"><strong>__getattribute__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__getattribute__">__getattribute__</a>('name')&nbsp;&lt;==&gt;&nbsp;x.name</tt></dd></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__getitem__"><strong>__getitem__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__getitem__">__getitem__</a>(y)&nbsp;&lt;==&gt;&nbsp;x[y]</tt></dd></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__getslice__"><strong>__getslice__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__getslice__">__getslice__</a>(i,&nbsp;j)&nbsp;&lt;==&gt;&nbsp;x[i:j]<br>
+&nbsp;<br>
+Use&nbsp;of&nbsp;negative&nbsp;indices&nbsp;is&nbsp;not&nbsp;supported.</tt></dd></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__reduce__"><strong>__reduce__</strong></a>(...)</dt></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__repr__"><strong>__repr__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__repr__">__repr__</a>()&nbsp;&lt;==&gt;&nbsp;repr(x)</tt></dd></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__setattr__"><strong>__setattr__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__setattr__">__setattr__</a>('name',&nbsp;value)&nbsp;&lt;==&gt;&nbsp;x.name&nbsp;=&nbsp;value</tt></dd></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__setstate__"><strong>__setstate__</strong></a>(...)</dt></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__str__"><strong>__str__</strong></a>(...)</dt><dd><tt>x.<a href="#AccessTokenRefreshError-__str__">__str__</a>()&nbsp;&lt;==&gt;&nbsp;str(x)</tt></dd></dl>
+
+<dl><dt><a name="AccessTokenRefreshError-__unicode__"><strong>__unicode__</strong></a>(...)</dt></dl>
+
+<hr>
+Data descriptors inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:<br>
+<dl><dt><strong>__dict__</strong></dt>
+</dl>
+<dl><dt><strong>args</strong></dt>
+</dl>
+<dl><dt><strong>message</strong></dt>
+</dl>
+</td></tr></table> <p>
+<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
+<tr bgcolor="#ffc8d8">
+<td colspan=3 valign=bottom>&nbsp;<br>
 <font color="#000000" face="helvetica, arial"><a name="Credentials">class <strong>Credentials</strong></a>(<a href="__builtin__.html#object">__builtin__.object</a>)</font></td></tr>
     
 <tr bgcolor="#ffc8d8"><td rowspan=2><tt>&nbsp;&nbsp;&nbsp;</tt></td>
@@ -338,6 +400,67 @@
 <table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
 <tr bgcolor="#ffc8d8">
 <td colspan=3 valign=bottom>&nbsp;<br>
+<font color="#000000" face="helvetica, arial"><a name="FlowExchangeError">class <strong>FlowExchangeError</strong></a>(<a href="oauth2client.client.html#Error">Error</a>)</font></td></tr>
+    
+<tr bgcolor="#ffc8d8"><td rowspan=2><tt>&nbsp;&nbsp;&nbsp;</tt></td>
+<td colspan=2><tt><a href="#Error">Error</a>&nbsp;occurred&nbsp;during&nbsp;request.<br>&nbsp;</tt></td></tr>
+<tr><td>&nbsp;</td>
+<td width="100%"><dl><dt>Method resolution order:</dt>
+<dd><a href="oauth2client.client.html#FlowExchangeError">FlowExchangeError</a></dd>
+<dd><a href="oauth2client.client.html#Error">Error</a></dd>
+<dd><a href="exceptions.html#Exception">exceptions.Exception</a></dd>
+<dd><a href="exceptions.html#BaseException">exceptions.BaseException</a></dd>
+<dd><a href="__builtin__.html#object">__builtin__.object</a></dd>
+</dl>
+<hr>
+Data descriptors inherited from <a href="oauth2client.client.html#Error">Error</a>:<br>
+<dl><dt><strong>__weakref__</strong></dt>
+<dd><tt>list&nbsp;of&nbsp;weak&nbsp;references&nbsp;to&nbsp;the&nbsp;object&nbsp;(if&nbsp;defined)</tt></dd>
+</dl>
+<hr>
+Methods inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
+<dl><dt><a name="FlowExchangeError-__init__"><strong>__init__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__init__">__init__</a>(...)&nbsp;initializes&nbsp;x;&nbsp;see&nbsp;x.__class__.__doc__&nbsp;for&nbsp;signature</tt></dd></dl>
+
+<hr>
+Data and other attributes inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
+<dl><dt><strong>__new__</strong> = &lt;built-in method __new__ of type object&gt;<dd><tt>T.<a href="#FlowExchangeError-__new__">__new__</a>(S,&nbsp;...)&nbsp;-&gt;&nbsp;a&nbsp;new&nbsp;<a href="__builtin__.html#object">object</a>&nbsp;with&nbsp;type&nbsp;S,&nbsp;a&nbsp;subtype&nbsp;of&nbsp;T</tt></dl>
+
+<hr>
+Methods inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:<br>
+<dl><dt><a name="FlowExchangeError-__delattr__"><strong>__delattr__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__delattr__">__delattr__</a>('name')&nbsp;&lt;==&gt;&nbsp;del&nbsp;x.name</tt></dd></dl>
+
+<dl><dt><a name="FlowExchangeError-__getattribute__"><strong>__getattribute__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__getattribute__">__getattribute__</a>('name')&nbsp;&lt;==&gt;&nbsp;x.name</tt></dd></dl>
+
+<dl><dt><a name="FlowExchangeError-__getitem__"><strong>__getitem__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__getitem__">__getitem__</a>(y)&nbsp;&lt;==&gt;&nbsp;x[y]</tt></dd></dl>
+
+<dl><dt><a name="FlowExchangeError-__getslice__"><strong>__getslice__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__getslice__">__getslice__</a>(i,&nbsp;j)&nbsp;&lt;==&gt;&nbsp;x[i:j]<br>
+&nbsp;<br>
+Use&nbsp;of&nbsp;negative&nbsp;indices&nbsp;is&nbsp;not&nbsp;supported.</tt></dd></dl>
+
+<dl><dt><a name="FlowExchangeError-__reduce__"><strong>__reduce__</strong></a>(...)</dt></dl>
+
+<dl><dt><a name="FlowExchangeError-__repr__"><strong>__repr__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__repr__">__repr__</a>()&nbsp;&lt;==&gt;&nbsp;repr(x)</tt></dd></dl>
+
+<dl><dt><a name="FlowExchangeError-__setattr__"><strong>__setattr__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__setattr__">__setattr__</a>('name',&nbsp;value)&nbsp;&lt;==&gt;&nbsp;x.name&nbsp;=&nbsp;value</tt></dd></dl>
+
+<dl><dt><a name="FlowExchangeError-__setstate__"><strong>__setstate__</strong></a>(...)</dt></dl>
+
+<dl><dt><a name="FlowExchangeError-__str__"><strong>__str__</strong></a>(...)</dt><dd><tt>x.<a href="#FlowExchangeError-__str__">__str__</a>()&nbsp;&lt;==&gt;&nbsp;str(x)</tt></dd></dl>
+
+<dl><dt><a name="FlowExchangeError-__unicode__"><strong>__unicode__</strong></a>(...)</dt></dl>
+
+<hr>
+Data descriptors inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:<br>
+<dl><dt><strong>__dict__</strong></dt>
+</dl>
+<dl><dt><strong>args</strong></dt>
+</dl>
+<dl><dt><strong>message</strong></dt>
+</dl>
+</td></tr></table> <p>
+<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
+<tr bgcolor="#ffc8d8">
+<td colspan=3 valign=bottom>&nbsp;<br>
 <font color="#000000" face="helvetica, arial"><a name="OAuth2Credentials">class <strong>OAuth2Credentials</strong></a>(<a href="oauth2client.client.html#Credentials">Credentials</a>)</font></td></tr>
     
 <tr bgcolor="#ffc8d8"><td rowspan=2><tt>&nbsp;&nbsp;&nbsp;</tt></td>
@@ -468,12 +591,13 @@
 otherwise&nbsp;pass&nbsp;in&nbsp;the&nbsp;query&nbsp;parameters&nbsp;received<br>
 at&nbsp;the&nbsp;callback&nbsp;uri&nbsp;to&nbsp;step2_exchange.</tt></dd></dl>
 
-<dl><dt><a name="OAuth2WebServerFlow-step2_exchange"><strong>step2_exchange</strong></a>(self, code)</dt><dd><tt>Exhanges&nbsp;a&nbsp;code&nbsp;for&nbsp;<a href="#OAuth2Credentials">OAuth2Credentials</a>.<br>
+<dl><dt><a name="OAuth2WebServerFlow-step2_exchange"><strong>step2_exchange</strong></a>(self, code, http<font color="#909090">=None</font>)</dt><dd><tt>Exhanges&nbsp;a&nbsp;code&nbsp;for&nbsp;<a href="#OAuth2Credentials">OAuth2Credentials</a>.<br>
 &nbsp;<br>
 Args:<br>
 &nbsp;&nbsp;code:&nbsp;string&nbsp;or&nbsp;dict,&nbsp;either&nbsp;the&nbsp;code&nbsp;as&nbsp;a&nbsp;string,&nbsp;or&nbsp;a&nbsp;dictionary<br>
 &nbsp;&nbsp;&nbsp;&nbsp;of&nbsp;the&nbsp;query&nbsp;parameters&nbsp;to&nbsp;the&nbsp;redirect_uri,&nbsp;which&nbsp;contains<br>
-&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;code.</tt></dd></dl>
+&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;code.<br>
+&nbsp;&nbsp;http:&nbsp;httplib2.Http,&nbsp;optional&nbsp;http&nbsp;instance&nbsp;to&nbsp;use&nbsp;to&nbsp;do&nbsp;the&nbsp;fetch</tt></dd></dl>
 
 <hr>
 Data descriptors inherited from <a href="oauth2client.client.html#Flow">Flow</a>:<br>
@@ -487,67 +611,6 @@
 <table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
 <tr bgcolor="#ffc8d8">
 <td colspan=3 valign=bottom>&nbsp;<br>
-<font color="#000000" face="helvetica, arial"><a name="RequestError">class <strong>RequestError</strong></a>(<a href="oauth2client.client.html#Error">Error</a>)</font></td></tr>
-    
-<tr bgcolor="#ffc8d8"><td rowspan=2><tt>&nbsp;&nbsp;&nbsp;</tt></td>
-<td colspan=2><tt><a href="#Error">Error</a>&nbsp;occurred&nbsp;during&nbsp;request.<br>&nbsp;</tt></td></tr>
-<tr><td>&nbsp;</td>
-<td width="100%"><dl><dt>Method resolution order:</dt>
-<dd><a href="oauth2client.client.html#RequestError">RequestError</a></dd>
-<dd><a href="oauth2client.client.html#Error">Error</a></dd>
-<dd><a href="exceptions.html#Exception">exceptions.Exception</a></dd>
-<dd><a href="exceptions.html#BaseException">exceptions.BaseException</a></dd>
-<dd><a href="__builtin__.html#object">__builtin__.object</a></dd>
-</dl>
-<hr>
-Data descriptors inherited from <a href="oauth2client.client.html#Error">Error</a>:<br>
-<dl><dt><strong>__weakref__</strong></dt>
-<dd><tt>list&nbsp;of&nbsp;weak&nbsp;references&nbsp;to&nbsp;the&nbsp;object&nbsp;(if&nbsp;defined)</tt></dd>
-</dl>
-<hr>
-Methods inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
-<dl><dt><a name="RequestError-__init__"><strong>__init__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__init__">__init__</a>(...)&nbsp;initializes&nbsp;x;&nbsp;see&nbsp;x.__class__.__doc__&nbsp;for&nbsp;signature</tt></dd></dl>
-
-<hr>
-Data and other attributes inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
-<dl><dt><strong>__new__</strong> = &lt;built-in method __new__ of type object&gt;<dd><tt>T.<a href="#RequestError-__new__">__new__</a>(S,&nbsp;...)&nbsp;-&gt;&nbsp;a&nbsp;new&nbsp;<a href="__builtin__.html#object">object</a>&nbsp;with&nbsp;type&nbsp;S,&nbsp;a&nbsp;subtype&nbsp;of&nbsp;T</tt></dl>
-
-<hr>
-Methods inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:<br>
-<dl><dt><a name="RequestError-__delattr__"><strong>__delattr__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__delattr__">__delattr__</a>('name')&nbsp;&lt;==&gt;&nbsp;del&nbsp;x.name</tt></dd></dl>
-
-<dl><dt><a name="RequestError-__getattribute__"><strong>__getattribute__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__getattribute__">__getattribute__</a>('name')&nbsp;&lt;==&gt;&nbsp;x.name</tt></dd></dl>
-
-<dl><dt><a name="RequestError-__getitem__"><strong>__getitem__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__getitem__">__getitem__</a>(y)&nbsp;&lt;==&gt;&nbsp;x[y]</tt></dd></dl>
-
-<dl><dt><a name="RequestError-__getslice__"><strong>__getslice__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__getslice__">__getslice__</a>(i,&nbsp;j)&nbsp;&lt;==&gt;&nbsp;x[i:j]<br>
-&nbsp;<br>
-Use&nbsp;of&nbsp;negative&nbsp;indices&nbsp;is&nbsp;not&nbsp;supported.</tt></dd></dl>
-
-<dl><dt><a name="RequestError-__reduce__"><strong>__reduce__</strong></a>(...)</dt></dl>
-
-<dl><dt><a name="RequestError-__repr__"><strong>__repr__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__repr__">__repr__</a>()&nbsp;&lt;==&gt;&nbsp;repr(x)</tt></dd></dl>
-
-<dl><dt><a name="RequestError-__setattr__"><strong>__setattr__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__setattr__">__setattr__</a>('name',&nbsp;value)&nbsp;&lt;==&gt;&nbsp;x.name&nbsp;=&nbsp;value</tt></dd></dl>
-
-<dl><dt><a name="RequestError-__setstate__"><strong>__setstate__</strong></a>(...)</dt></dl>
-
-<dl><dt><a name="RequestError-__str__"><strong>__str__</strong></a>(...)</dt><dd><tt>x.<a href="#RequestError-__str__">__str__</a>()&nbsp;&lt;==&gt;&nbsp;str(x)</tt></dd></dl>
-
-<dl><dt><a name="RequestError-__unicode__"><strong>__unicode__</strong></a>(...)</dt></dl>
-
-<hr>
-Data descriptors inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:<br>
-<dl><dt><strong>__dict__</strong></dt>
-</dl>
-<dl><dt><strong>args</strong></dt>
-</dl>
-<dl><dt><strong>message</strong></dt>
-</dl>
-</td></tr></table> <p>
-<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
-<tr bgcolor="#ffc8d8">
-<td colspan=3 valign=bottom>&nbsp;<br>
 <font color="#000000" face="helvetica, arial"><a name="Storage">class <strong>Storage</strong></a>(<a href="__builtin__.html#object">__builtin__.object</a>)</font></td></tr>
     
 <tr bgcolor="#ffc8d8"><td rowspan=2><tt>&nbsp;&nbsp;&nbsp;</tt></td>