@_WithLock
  def OldestTask(self):
    if self._sorted_by_eta:
      return self._sorted_by_eta[0][2]
    return None
VSIDS Heuristic Calculation
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/taskqueue/taskqueue_stub.py/_Queue.OldestTask--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/logic/algorithms/dpll2.py/SATSolver._vsids_calculate