code: public NucleotideCompound getAmbiguity(NucleotideCompound... compounds) {
  		Set<NucleotideCompound> settedCompounds = new HashSet<NucleotideCompound>();
  		for(NucleotideCompound compound: compounds) {
  			for(NucleotideCompound subCompound: compound.getConstituents()) {
  				settedCompounds.add(getCompoundForString(subCompound.getBase().toUpperCase()));
  			}
  		}
  		for(NucleotideCompound compound: getAllCompounds()) {
  			if(compound.getConstituents().equals(settedCompounds)) {
  				return compound;
  			}
  		}
  		return null;
  	}
docs: Calculates the best symbol for a collection of compounds. For example
  if you gave this method a AC it will return a M which is the ambiguity
  symbol for these compounds.
  
  @param compounds Compounds to calculate ambiguity for
  @return The ambiguity symbol which represents this set of nucleotides best