Set the values in this set instance to the indexing values of
the passed DataFrame. The number of indexing columns of the
parameter must be equal to the arity of this set instance.
For example, considering the following AMPL entities and corresponding
C++ objects:
set A := 1..2;
param p{i in A} := i+10;
set AA;
The following is valid:
ampl::Set A = ampl.getSet(“A”), AA = ampl.getSet(“AA”);
AA.setValues(A.getValues()); // A has now the members {1, 2}