How to find process definitions with a specific StartSignalEvent name?

[jwestra]

I want to list all the process definitions that start with a certain signal name.

I found ExecutionService can find signals for an execution instance.  That's not what I need.  I found something similar to what I need on the ProcessDefinitionQuery.  It has a method where you can find the process definitions for a message subscription:

/**
   * Selects the single process definition which has a start message event 
   * with the messageName.
   */
  ProcessDefinitionQuery messageEventSubscriptionName(String messageName);
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I need something similar like: signalEventSubscriptionName(String signalEventName)

What class can I find this or how do I create one on my own using custom SQL?

[jbarrez]

There is a (non-public) EventSubscriptionQueryImpl class you can use for this.
The idea is that this class will be public in the future.