code: function(a, b, aParent, bParent, prop, compares, options){
  		var subsetCompare = function(a, b, aParent, bParent, prop){
  			var compare = compares[prop] === undefined ? compares['*'] : compares[prop];
  
  			if (! loop(a, b, aParent, bParent, prop, compare, options ) ) {
  				var subsetCheck;
  				if( !(prop in aParent)) {
  					subsetCheck = "subsetB";
  				}
  				if( !(prop in bParent) ) {
  					subsetCheck = "subsetA";
  				}
  				if(subsetCheck) {
  					if( !options.subset ) {
  						options.subset = subsetCheck;
  					}
  					return options.subset === subsetCheck ? undefined: false;
  				}
  
  				return false;
  			}
  		};
  
  		var aType = typeof a;
  		if(aType === 'object' || aType === 'function') {
  			return h.eachInUnique(a, subsetCompare, b, subsetCompare, true);
  		}
  	}
docs: if everything is the same OR doesn't have a property on the left or right (only)