Document everlasting expectations

docs/reference/scenarios_and_fake_objects.rst

@@ -211,6 +211,25 @@ This demands that the fake is called with ``'b'`` only *after* it was called wit
 
 The code in ``my_code()`` passes this test.
 
+Of course you can still use the ``>>`` operator to specify return values for your expectation.
+
+Everlasting Expectations
+------------------------
+
+Sometimes we don't want to test for a specific number of calls, but 
+we do want to make sure that a function call is of a particular form.
+
+We can modify an ``.unordered()`` expectation with ``.everlasting()`` and 
+this essentially modifies the expectation to mean "this call is expected zero or more times, in any order".
+
+Here's a small example
+
+.. literalinclude:: test_everlasting.py
+   :linenos:
+   :emphasize-lines: 7,13-15,18,21-22
+
+Of course you can still use the ``>>`` operator to specify return values for your expectation.
+
 
 Context Manager Expectations
 ============================

docs/reference/test_everlasting.py

@@ -0,0 +1,22 @@
+from testix import *
+
+def test_unordered_expecation():
+    with Scenario() as s:
+        s.some_object('a')
+        s.some_object('b')
+        s.some_object('c').unordered().everlasting()
+
+        my_fake = Fake('some_object')
+        my_code(my_fake)
+
+def my_code(x):
+    x('c')
+    x('c')
+    x('c')
+
+    x('a')
+    x('c')
+    x('b')
+
+    x('c')
+    x('c')