Как в Docker узнать сколько готовящихся изменений будет в коменте?

Этой командой можно посмотреть сколько изменений в образе:

root@localhost:~# docker history voipnovatos/asterisk-13                                                                                                
IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT                                     
ae1b3a5713a8        4 months ago        /bin/sh -c #(nop) EXPOSE 5080/udp               0 B                                                             
<missing>           4 months ago        /bin/sh -c #(nop) CMD ["/root/config.sh"]       0 B                                                             
<missing>           4 months ago        /bin/sh -c chmod a+x /root/config.sh            641 B                                                           
<missing>           4 months ago        /bin/sh -c #(nop) COPY file:2489027413c11e268   641 B                                                           
<missing>           4 months ago        /bin/sh -c ./configure; make; make install; m   476.8 MB                                                        
<missing>           4 months ago        /bin/sh -c #(nop) WORKDIR /asterisk-13.10.0     0 B                                                             
<missing>           4 months ago        /bin/sh -c curl -s http://downloads.asterisk.   69.47 MB                                                        
<missing>           4 months ago        /bin/sh -c apt-get install -y build-essential   254.1 MB                                                        
<missing>           4 months ago        /bin/sh -c apt-get update                       9.773 MB                                                        
<missing>           4 months ago        /bin/sh -c #(nop) ENV RTP_PORT_END=10150        0 B                                                             
<missing>           4 months ago        /bin/sh -c #(nop) ENV RTP_PORT_START=10000      0 B                                                             
<missing>           4 months ago        /bin/sh -c #(nop) ENV SIP_PORT=5080             0 B                                                             
<missing>           4 months ago        /bin/sh -c #(nop) ENV DEBIAN_FRONTEND=noninte   0 B                                                             
<missing>           4 months ago        /bin/sh -c #(nop) ENV build_date=2016-07-25     0 B                                                             
<missing>           4 months ago        /bin/sh -c #(nop) MAINTAINER Alberto Sagredo    0 B                                                             
<missing>           5 months ago        /bin/sh -c #(nop) CMD ["/bin/bash"]             0 B                                                             
<missing>           5 months ago        /bin/sh -c #(nop) ADD file:76679eeb94129df23c   125.1 MB