How to determine Mod(a,b) with t_COMPLEX b?

[hermann@stamm-wilbrandt.de]

$ gp -q
? a=1+4*I;b=3+2*I;
? a/b
11/13 + 10/13*I
? Mod(a,b)
  ***   at top-level: Mod(a,b)
  ***                 ^--------
  *** Mod: forbidden division t_COMPLEX % t_COMPLEX.
  ***   Break loop: type 'break' to go back to GP prompt
break>


The minimal residue of 1+4*I modulo 3+2*I is the yellow point -I in the 
example:
https://en.wikipedia.org/wiki/Gaussian_integer#Describing_residue_classes

How can minimal residue of an input gaussian integer modulo a gaussian 
integer be computed in PARI/GP?

Regards,

Hermann.