bootstrapvalidator for checkbox

Question

I have a checkbox control which is dynamically filled. There are 3 checkboxes in the group. I am trying to check if at least one checkbox is selected, when user clicks on submit button. I have tried the below code, but I am not getting the error, and the page is getting saved. Below is the UI code

 <input type="checkbox" id="{{method.id}}" value="{{method.value}}"
        name="deliveryMethod[]" ng-model="method.selected"
        ng-click="toggleSelection(method.value)" 
        ng-required="value.length==0"> {{method.value}}

In the js file, i tried as below:

jQuery("#createForm").bootstrapValidator({
        framework: 'bootstrap',
        excluded: [':disabled', ':hidden', ':not(:visible)'],
        icon: {
            valid: 'glyphicon glyphicon-ok',
            invalid: 'glyphicon glyphicon-remove',
            validating: 'glyphicon glyphicon-refresh'
        },
        fields: {
            TypeSelect: {
                validators: {
                    callback: {
                        message: 'Please select the type',
                        callback: function (value, validator, $field) {                        
                            var options = validator.getFieldElements('testTypeSelect').val();
                            return (options != null && options.length >= 1);
                        }
                    }
                }
            },
            testName: {
                validators: {
                    notEmpty: {
                        message: 'name required.'
                    }
                }

            },

"deliveryMethod[]": { 
                validators: { 
                    required: true, 
                    minlength: 1, 
                    maxlength: 3, 
                message: 'Delivery Type is Mandatory.' 
                } 
            },
   }

How to make at least one checkbox is checked, if not show the message. Thanks