Once a LogFile has been added to a BuildStep with addLog(),
addCompleteLog(), addHTMLLog(), or logfiles=,
your BuildStep can retrieve it by using getLog():
     class MyBuildStep(ShellCommand):
         logfiles = { "nodelog": "_test/node.log" }
     
         def evaluateCommand(self, cmd):
             nodelog = self.getLog("nodelog")
             if "STARTED" in nodelog.getText():
                 return SUCCESS
             else:
                 return FAILURE
   For a complete list of the methods you can call on a LogFile, please
see the docstrings on the IStatusLog class in
buildbot/interfaces.py.