code: public boolean isSubsetOf(Multiset<O> multiset) throws ParameterException {
  		Validate.notNull(multiset);
  		for (O o : multiplicities.keySet()) {
  			if (multiplicity(o) > multiset.multiplicity(o)) {
  				return false;
  			}
  		}
  		return true;
  	}
docs: Checks if this multiset is a subset of the given multiset.<br>
  A multiset m1 is a subset of another multiset m2 if for every object
  o:<br>
  m1.multiplicity(o) <= m2.multiplicity(o). @param multiset T
  
  he given multiset. @param multiset @return <code>true</code> if this
  multiset
  
  i
  s a subset of the given multiset;<br>
  <code>false</code> otherwise.
  @throws ParameterException