added comment to DropMask
from keras.layers import Layer
class DropMask(Layer):
+ """
+ Sometimes we know that a mask is always going to contain 1s (and never 0s)
+ due to e.g. slicing the beginning of a sequence with a known min length.
+ In that case it can be useful to drop the sequence mask and feed the
+ activations to a layer which does not support masking (e.g. Dense).
+ """
supports_masking = True
def call(self, x, mask):
