diff --git a/devstack/functions.sh b/devstack/functions.sh
new file mode 100644
index 0000000..026f527
--- /dev/null
+++ b/devstack/functions.sh
@@ -0,0 +1,32 @@
+# Generic use functions
+
+# ensure we don't re-source this in the same environment
+[[ -z "$_NEUTRON_TEMPEST_PLUGIN_FUNCTIONS" ]] || return 0
+declare -r -g _NEUTRON_TEMPEST_PLUGIN_FUNCTIONS=1
+
+# Create a function copying the code from an existing one
+function save_function {
+    local old_name=$1
+    local new_name=$2
+
+    # Saving the same function again after redefining it could produce a
+    # recorsive function in case for example this plugin is sourced twice
+    if type -t "${new_name}"; then
+        # Prevent copying the same function twice
+        return 0
+    fi
+
+    # Save xtrace setting
+    _XTRACE_FUNCTIONS=$(set +o | grep xtrace)
+    set +o xtrace
+
+    # Get code of the original function
+    local old_code=$(declare -f ${old_name})
+    # Produce code for the new function
+    local new_code="${new_name}${old_code#${old_name}}"
+    # Define the new function
+    eval "${new_code}"
+
+    # Restore xtrace
+    $_XTRACE_FUNCTIONS
+}