'Propagates the given input through this layer (and only this layer).
Parameters
input : Theano expression
The expression to propagate through this layer.
Returns
output : Theano expression
The output of this layer given the input to this layer.
Notes
This is called by the base :meth:`lasagne.layers.get_output()`
to propagate data through a network.
This method should be overridden when implementing a new
:class:`Layer` class. By default it raises `NotImplementedError`.'

def get_output_for(self, input, **kwargs):

    raise NotImplementedError
