,---------------------------------------.
         ,------.  |IEEE Std. 802.1AS-2011 clause 10.3.12.2|
         |*start|  |---------------------------------------|
         |------|  |PortRoleSelection state machine        |
         `------'  |                                       |
             |     `---------------------------------------'
             |                                              
             |                                              
,------------------------.                                  
|INIT_BRIDGE             |                                  
|------------------------|                                  
|updateRoleDisabledTree()|                                  
`------------------------'                                  
             |                                              
  ,-------------------.                                     
  |ROLE_SELECTION     |                                     
  |-------------------|                                     
  |clearReselectTree()|                                     
  |updateRolesTree()  |                                     
  |setSelectedTree()  |                                     
  `-------------------'