The question with the Capacitance measurement is how to define the starting point for the measurement, as the charging the capacitor via the 0.5uA to 1mA current source is made in time, and the optimal option is to have the capacitor discharged to zero volts. Then you simply make DCV sampling with a NPLC speed (class 0), till the voltage reaches a max voltage, or, you may do a fixed number of DCV samples within a sweep. Then you calculate the slope of the sampled voltage ramp and from that you get the capacitance. The autoranging from 1nF to 10mF (34410A) would require to alter the constant current value and perhaps NPLC before the ramp sweep to stay in an "optimal" DCV range. The question is how to discharge the capacitor, or how to define the "start" of a sweep. There is a lot of switches inside, they may use a lot of tricks..
PS: for example the const current 0.5uA charges 1nF in 20ms to 10V, while 1mA charges 10mF in 1s to 100mV (all from a discharged capacitor).