--- a/genshi/filters/i18n.py
+++ b/genshi/filters/i18n.py
@@ -347,6 +347,8 @@
     def __init__(self, params=u'', lineno=-1):
         """Initialize the message buffer.
         
+        :param params: comma-separated list of parameter names
+        :type params: `basestring`
         :param lineno: the line number on which the first stream event
                        belonging to the message was found
         """
@@ -463,6 +465,7 @@
 
     return parts
 
+
 def extract_from_code(code, gettext_functions):
     """Extract strings from Python bytecode.
     
@@ -506,6 +509,7 @@
                     yield funcname, strings
     return _walk(code.ast)
 
+
 def extract(fileobj, keywords, comment_tags, options):
     """Babel extraction method for Genshi templates.