Update example code to 2018 edition
diff --git a/src/expr.rs b/src/expr.rs
index 62c4832..d07070f 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -2292,10 +2292,7 @@
         /// # Example
         ///
         /// ```
-        /// #[macro_use]
-        /// extern crate syn;
-        ///
-        /// use syn::{token, Attribute, Block, Ident, Result, Stmt};
+        /// use syn::{braced, token, Attribute, Block, Ident, Result, Stmt, Token};
         /// use syn::parse::{Parse, ParseStream};
         ///
         /// // Parse a function with no generics or parameter list.
@@ -2337,8 +2334,6 @@
         ///         })
         ///     }
         /// }
-        /// #
-        /// # fn main() {}
         /// ```
         pub fn parse_within(input: ParseStream) -> Result<Vec<Stmt>> {
             let mut stmts = Vec::new();