* Expected keys are in format custom_fieldID:recordID or custom_groupName:fieldName:recordID.
*
* @example:
- * @code
+ * ```
* // entity ID. You do not need to specify entity type, we figure it out based on the fields you're using
* 'entity_id' => 123,
* // (omitting :id) inserts or updates a field in a single-valued group
* 'custom_some_group:my_field' => 'myinfo',
* // updates record ID 8 in my_other_field in multi-valued some_big_group
* 'custom_some_big_group:my_other_field:8' => 'myinfo',
- * @endcode
+ * ```
*
* @throws Exception
* @return array