code: func sliceOfFieldNames(val interface{} /*, opts Options*/) (fieldNames []string) {
  	fields := structs.ListExportedFields(val, filterOutPK)
  	fieldNames = []string{}
  	for _, field := range fields {
  		fieldName, exported := fieldName(field)
  		if exported {
  			fieldNames = append(fieldNames, fieldName)
  		}
  	}
  
  	return fieldNames
  }
docs: // SliceOfFields generates slice of translated (cql tag) field names
  // used in creating update statement only