Inserts len elements into a GArray at the given index.
If index_ is greater than the array’s current length, the array is expanded.
The elements between the old end of the array and the newly inserted elements
will be initialised to zero if the array was configured to clear elements;
otherwise their values will be undefined.
data may be NULL if (and only if) len is zero. If len is zero, this
function is a no-op.
Inserts len elements into a GArray at the given index.
If index_ is greater than the array’s current length, the array is expanded. The elements between the old end of the array and the newly inserted elements will be initialised to zero if the array was configured to clear elements; otherwise their values will be undefined.
data may be NULL if (and only if) len is zero. If len is zero, this function is a no-op.