<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def updateBoostStrength(m):
 """ Function used to update KWinner modules boost strength after each epoch. Call using :meth:`torch.nn.Module.apply` after each epoch if required For example: ``m.apply(updateBoostStrength)`` :param m: KWinner module """

  if isinstance(m, KWinnersBase):
    if m.training:
      m.boostStrength = m.boostStrength * m.boostStrengthFactor