code: public void testQueryByProcessDefinitionKeyIn(){
    Set<String> includeIds=new HashSet<String>();
    assertEquals(14,runtimeService.createExecutionQuery().processDefinitionKeys(includeIds).list().size());
    includeIds.add(CONCURRENT_PROCESS_KEY);
    assertEquals(12,runtimeService.createExecutionQuery().processDefinitionKeys(includeIds).list().size());
    includeIds.add(SEQUENTIAL_PROCESS_KEY);
    assertEquals(14,runtimeService.createExecutionQuery().processDefinitionKeys(includeIds).list().size());
    includeIds.add("invalid");
    assertEquals(14,runtimeService.createExecutionQuery().processDefinitionKeys(includeIds).list().size());
    includeIds.clear();
    includeIds.add("invalid");
    assertEquals(0,runtimeService.createExecutionQuery().processDefinitionKeys(includeIds).list().size());
  }
  