code: function getPotentialWildcardMatches ( keypath ) {
    	var keys, starMap, mapper, i, result, wildcardKeypath;
  
    	keys = splitKeypathI( keypath );
    	if( !( starMap = starMaps[ keys.length ]) ) {
    		starMap = getStarMap( keys.length );
    	}
  
    	result = [];
  
    	mapper = function ( star, i ) {
    		return star ? '*' : keys[i];
    	};
  
    	i = starMap.length;
    	while ( i-- ) {
    		wildcardKeypath = starMap[i].map( mapper ).join( '.' );
  
    		if ( !result.hasOwnProperty( wildcardKeypath ) ) {
    			result.push( wildcardKeypath );
    			result[ wildcardKeypath ] = true;
    		}
    	}
  
    	return result;
    }
docs: This function takes a keypath such as 'foo.bar.baz', and returns all the variants of that keypath that include a wildcard in place of a key, such as 'foo.bar.*', 'foo.*.baz', 'foo.*.*' and so on. These are then checked against the dependants map (ractive.viewmodel.depsMap) to see if any pattern observers are downstream of one or more of these wildcard keypaths (e.g. 'foo.bar.*.status')