code: @Override
      protected Expression and(Part part, Expression base, Iterator<Object> iterator) {
          return Expr.and(base, toExpression(part, root));
      }
docs: /*
  (non-Javadoc)
  @see org.springframework.data.repository.query.parser.AbstractQueryCreator#and(org.springframework.data.repository.query.parser.Part, java.lang.Object, java.util.Iterator)