Add empty_pathmover; empty_strategy

ops_intro_usage/empty_pathmover.py

+class MyPathMover(paths.PathMover):
+    def __init__(self, ensemble, my_option):
+        # addition ensembles possible, 
+        super(MyPathMover, self).__init__()
+        self.ensemble = ensemble
+        self.my_option = my_option
+
+    def _called_ensembles(self):
+        # ensemble for input samples to __call__
+        return [self.ensemble]
+
+    def _get_in_ensembles(self):
+        # input ensembles
+        return [self.ensemble]
+
+    # _get_out_ensembles defaults to _get_in_ensembles
+
+    def __call__(self, sample_for_ensemble):
+        # additional samples possible
+        # do the stuff to make trial samples
+        details = {'my_detail': 'value'}
+        return [sample], details
+
+

ops_intro_usage/empty_strategy.py

+from openpathsampling.high_level import move_strategy
+
+class MyStrategy(move_strategy.MoveStrategy):
+    _level = move_strategy.levels.MOVER
+    def __init__(self, my_option, ensembles=None, group="group_name",
+                 replace=True):
+        super(MyStrategy, self).__init__(ensembles, group, replace)
+        self.my_option = my_option
+
+    def make_movers(self, scheme):
+        ensemble_list = self.get_init_ensembles(scheme)
+        # make a list of the movers
+        return mover_list