Add a blank check_fail_matcher implementation.

src/parser/new_context.rs

@@ -110,6 +110,10 @@ where
             fail_matcher: ChainBehavior::AndParent(Some(fail_matcher))
         })
     }
+
+    pub fn check_fail_matcher<'s>(&'r self, i: &'s str) -> IResult<&'s str, &'s str, VerboseError<&'s str>> {
+        todo!()
+    }
 }
 
 fn test_context() {