boon/src/main/java/org/boon/sort/Sort.java
private List<Comparator> childComparators( Map<String, FieldAccess> fields ) {
        if ( this.comparators == null ) {
            this.comparators = new ArrayList<>( this.sorts.size() + 1 );

            for ( Sort sort : sorts ) {
                Comparator comparator = universalComparator(
                        sort.getName(),
                        fields,
                        sort.getType(),
                        sort.childComparators(fields)
                );
                this.comparators.add( comparator );
            }
        }
        return this.comparators;
    }
private List<Comparator> childComparators( Map<String, FieldAccess> fields ) {
        if ( this.comparators == null ) {
            this.comparators = new ArrayList<>( this.sorts.size() + 1 );

            for ( Sort sort : sorts ) {
                Comparator comparator = universalComparator(
                        sort.getName(),
                        fields,
                        sort.getType(),
                        sort.childComparators(fields)
                );
                this.comparators.add( comparator );
            }
        }
        return this.comparators;
    }
This creates a list of children comparators based on the child list.
@param fields
@return