tf.keras.backend.sum( x, axis=None, keepdims=False )
Sum of the values in a tensor, alongside the specified axis.
x: A tensor or variable.
axis: An integer, the axis to sum over.
keepdims: A boolean, whether to keep the dimensions or not. If
False, the rank of the tensor is reduced by 1. If
True, the reduced dimension is retained with length 1.
A tensor with sum of