old_contents: 
  __version__ = '0.0.3'
  VERSION = __version__
  
  from . import time_frequency
  from . import backend
  from . import backend_keras
  
  from . import augmentation
  from . import filterbank
  from . import utils
  
  from keras import backend as K
  if K.backend() == 'theano':
      from . import stft
  
  
new_contents: __version__ = '0.0.3'
  VERSION = __version__
  
  from . import time_frequency
  from . import backend
  from . import backend_keras
  
  from . import augmentation
  from . import filterbank
  from . import utils
  
  from keras import backend as K
  
  if K.backend() == 'theano':
      try:
          from theano.tensor import fft
          from . import stft
      else:
      print('Update theano to 0.9 to use stft.')
  
subject: add theano version checker