def add_layer(self, layer=None, prev_layer=None, next_layer=None):
if len(self.layers) >= MAX_LAYERS_NUM:
return False
if (prev_layer is None) or (next_layer is None):
return False
if layer == None:
layer = Layer(next=next_layer)
else:
if (next_layer in layer.next_layer) or (prev_layer in layer.prev_layer):
print 'DA',
return False
self.layers.append(layer)
self.connect_layers(prev_layer, layer)
layer.modify(-1) # add random weight
return True
