def pos_sampling(i):
    s = tf.squeeze(tf.multinomial(tf.log(tf.expand_dims((pos_weights[i] + 1e-16), axis=0)), k, output_dtype=tf.int32), axis=0)
    return s
def pos_sampling(i):
    s = tf.squeeze(tf.multinomial(tf.log(tf.expand_dims((pos_weights[i] + 1e-16), axis=0)), k, output_dtype=tf.int32), axis=0)
    return s