driver-legacy/src/main/com/mongodb/QueryBuilder.java
@SuppressWarnings("unchecked")
    public QueryBuilder and(final DBObject... ands) {
        List l = (List) _query.get(QueryOperators.AND);
        if (l == null) {
            l = new ArrayList();
            _query.put(QueryOperators.AND, l);
        }
        Collections.addAll(l, ands);
        return this;
    }
@SuppressWarnings("unchecked")
    public QueryBuilder and(final DBObject... ands) {
        List l = (List) _query.get(QueryOperators.AND);
        if (l == null) {
            l = new ArrayList();
            _query.put(QueryOperators.AND, l);
        }
        Collections.addAll(l, ands);
        return this;
    }
Equivalent to an $and operand

@param ands the list of conditions to and together
@return {@code this}