public static IIncludeQuery <TEntity, TNewProperty> Include <TEntity, TPreviousProperty, TNewProperty>(this IIncludeQuery <TEntity, TPreviousProperty> query, Expression <Func <TEntity, TNewProperty> > selector)
        {
            query.Visitor.Visit(node: selector);

            var includeQuery = new IncludeQuery <TEntity, TNewProperty>(pathMap: query.PathMap);

            query.PathMap[key : includeQuery] = query.Visitor.Path;

            return(includeQuery);
        }
        public static IIncludeQuery <TEntity, TNewProperty> ThenInclude <TEntity, TPreviousProperty, TNewProperty>(this IIncludeQuery <TEntity, IEnumerable <TPreviousProperty> > query, Expression <Func <TPreviousProperty, TNewProperty> > selector)
        {
            query.Visitor.Visit(node: selector);

            // If the visitor did not generated a path, return a new IncludeQuery with an unmodified PathMap.
            if (string.IsNullOrEmpty(value: query.Visitor.Path))
            {
                return(new IncludeQuery <TEntity, TNewProperty>(pathMap: query.PathMap));
            }

            var pathMap      = query.PathMap;
            var existingPath = pathMap[key : query];

            pathMap.Remove(key: query);

            var includeQuery = new IncludeQuery <TEntity, TNewProperty>(pathMap: query.PathMap);

            pathMap[key : includeQuery] = $"{existingPath}.{query.Visitor.Path}";

            return(includeQuery);
        }