code: public static <C extends Compound> String getGCGType(CompoundSet<C> cs) {
  		return (cs == DNACompoundSet.getDNACompoundSet() || cs == AmbiguityDNACompoundSet.getDNACompoundSet()) ? "D" :
  			(cs == RNACompoundSet.getRNACompoundSet() || cs == AmbiguityRNACompoundSet.getRNACompoundSet()) ? "R" : "P";
  	}
docs: Determines GCG type
  @param cs compound set of sequences
  @return GCG type