MCAD API function problem while Geting Constr Data from ConstrDescrip.:

. . . . .
AmiConstraintType constrType;
as = amiGetData(pConstrDescrip, Ami::csAttConstrType, constrType);
if(constType == Ami::eCompInsert) {
AmiGeomKey *pGeomKey1 = NULL, *pGeomKey2 = NULL;
status = amiGetConstrOperands(pConstrKey, pGeomKey1, pGeomKey2);
AmiKeyType type1, type2;
status = amiGetKeyType(pGeomKey1, type1);
status = amiGetKeyType(pGeomKey2, type2);}
. . . .
//one get : type1 == Ami:laneKey && type2 == Ami:laneKey

//expected: type1 == Ami::arcKey && type2 == Ami::arcKey

Please, instruct me on how to extract specific operands from ConstrDescrip, which should be arcs or circular edges (circular faces is trivial case), since kPlane cannot be “inserted” !!!