diff --git a/src/namespace_set.rs b/src/namespace_set.rs
index a5401d1e5c94b6f599dab68efd6c7c022353f863..163a87304aadb1320e4ff4731f2a8f66614d97d6 100644
--- a/src/namespace_set.rs
+++ b/src/namespace_set.rs
@@ -36,7 +36,7 @@ impl NamespaceSet {
     pub fn declared_ns(&self) -> &BTreeMap<Option<String>, String> {
         &self.namespaces
     }
-    
+
     pub fn get(&self, prefix: &Option<String>) -> Option<String> {
         match self.namespaces.get(prefix) {
             Some(ns) => Some(ns.clone()),