array_expand

/**
 * Expands each value into entry, if there are more than one value, multiple rows will be created.
 * Array keys are ignored, only values are used to create new rows.
 * Nested in another function (structure(), concat(), ...) it still gives one row per element. Several
 * expands in one expression are zipped to the longest list; a shorter one gives null, so its element
 * type becomes nullable. It is refused inside another array_expand() and in filter(), until(),
 * duplicateRow(), aggregate(), over() and onEach().
 *
 * Before:
 *   +--+-------------------+
 *   |id|              array|
 *   +--+-------------------+
 *   | 1|{"a":1,"b":2,"c":3}|
 *   +--+-------------------+
 *
 * After:
 *   +--+--------+
 *   |id|expanded|
 *   +--+--------+
 *   | 1|       1|
 *   | 1|       2|
 *   | 1|       3|
 *   +--+--------+
 */
array_expand(ScalarFunction $function, ArrayExpand $expand) : ArrayExpand