code: function query_jsonSchema() {
    let populate = this._mongooseOptions.populate;
    if (populate) {
      populate = Object.keys(populate).map(k => populate[k]);
    }
    let jsonSchema = this.model.jsonSchema(
      this._fields, populate
    );
  
    delete jsonSchema.required;
  
    if (this.op.indexOf('findOne') === 0) return jsonSchema;
  
    delete jsonSchema.title;
  
    jsonSchema = {
      title: 'List of ' + plural(this.model.modelName),
      type: 'array',
      items: jsonSchema
    };
  
    if (this.options.limit) {
      jsonSchema.maxItems = this.options.limit
    }
  
    return jsonSchema;
  }
docs: query_jsonSchema - returns json schema considering the query type and options
  
  @return {Object}  json schema