Add documentation for CI_User_agent::parse()
diff --git a/user_guide_src/source/libraries/user_agent.rst b/user_guide_src/source/libraries/user_agent.rst
index 9f96768..af76cfa 100644
--- a/user_guide_src/source/libraries/user_agent.rst
+++ b/user_guide_src/source/libraries/user_agent.rst
@@ -223,4 +223,11 @@
:returns: array
- Returns an array of character sets accepted by the user agent.
\ No newline at end of file
+ Returns an array of character sets accepted by the user agent.
+
+ .. method:: parse($string)
+
+ :param string $string: A custom user-agent string
+ :returns: void
+
+ Parses a custom user-agent string, different from the one reported by the current visitor.
\ No newline at end of file