From 06000a4f2e9a2a2b2bf6455add97c25dd486a798 Mon Sep 17 00:00:00 2001
From: Salvatore Stella <sstella@ncsu.edu>
Date: Sat, 14 Jan 2017 01:47:53 +0100
Subject: [PATCH] Added missing doctest

---
 src/sage/algebras/cluster_algebra.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/sage/algebras/cluster_algebra.py b/src/sage/algebras/cluster_algebra.py
index 257bd0e0cbd..e8db19c1c60 100644
--- a/src/sage/algebras/cluster_algebra.py
+++ b/src/sage/algebras/cluster_algebra.py
@@ -1203,6 +1203,15 @@ class ClusterAlgebra(Parent, UniqueRepresentation):
 
     @staticmethod
     def __classcall__(self, data, **kwargs):
+        r"""
+        Preparse input to make it hashable.
+
+        EXAMPLES::
+
+        sage: A = ClusterAlgebra(['A', 2]); A   # indirect doctest
+        A Cluster Algebra with cluster variables x0, x1 and no coefficients
+         over Integer Ring
+        """
         Q = ClusterQuiver(data)
         for key in kwargs:
             if isinstance(kwargs[key],list):