[GiNaC-list] Any way to get the leading order of a series expansion?

Hi, all. We have some code needs to have the first N orders of a series expansion of an expression; so far we've been actually using sympy for this: there one can use series() [1] directly, as it computes "the first N orders", whereas in GiNaC series() expands "up to N-th order", so if I just need e.g. the leading order, then series() can't help me directly. Any idea of how can one get the leading order, or the first N orders with GiNaC? Would this need a lot of effort to implement? [1] https://docs.sympy.org/latest/modules/series/series.html#sympy.series.series...