Behavior tree for robotics applications

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I'm writing a behavior tree (BT) for my robot which will wait for mode choosing and proceed the chosen mode. Here I use a Sequence node, the first child node will wait for a service call to /choose_mode service and then output the mode, the second child node is Switch node and will take the output as input, then proceed the corresponding mode. Is there a standard BT structure for this case, and can you guys suggest documents about BT for robotics applications? Thanks.