From bccfe355878dd7a231de70fd993e2eb866a2cf03 Mon Sep 17 00:00:00 2001
From: Marc Addeo <marcaddeo@gmail.com>
Date: Sun, 12 Nov 2017 12:01:39 -0500
Subject: [PATCH] Add a cause() method to EmitError

For compatibility with error_chain
---
 saphyr/src/emitter.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/saphyr/src/emitter.rs b/saphyr/src/emitter.rs
index ef3cdc7..332ff9e 100644
--- a/saphyr/src/emitter.rs
+++ b/saphyr/src/emitter.rs
@@ -17,6 +17,10 @@ impl Error for EmitError {
             EmitError::BadHashmapKey => "bad hashmap key",
         }
     }
+
+    fn cause(&self) -> Option<&Error> {
+        None
+    }
 }
 
 impl Display for EmitError {