add disable_cachew helper

my/core/cachew.py

@@ -0,0 +1,29 @@
+'''
+# TODO this probably belongs to cachew? or cachew.experimental
+'''
+from contextlib import contextmanager
+
+
+def disable_cachew():
+    '''
+    NOTE: you need to use it before importing any function using @cachew.cachew
+    '''
+    # TODO not sure... maybe it should instead use some hook.. it's a ibt ugly do
+    import cachew
+
+    @cachew.doublewrap
+    def cachew_off(func=None, *args, **kwargs):
+        return func
+    old = cachew.cachew
+    cachew.cachew = cachew_off
+    return old
+
+
+@contextmanager
+def disabled_cachew():
+    import cachew
+    old = disable_cachew()
+    try:
+        yield
+    finally:
+        cachew.cachew = old