lastIndexOf method Null safety

int lastIndexOf (
  1. E element,
  2. [int? start]

The last index of element in this list.

Searches the list backwards from index start to 0.

The first time an object o is encountered so that o == element, the index of o is returned.

var notes = ['do', 're', 'mi', 're'];
notes.lastIndexOf('re', 2); // 1

If start is not provided, this method searches from the end of the list.

notes.lastIndexOf('re');  // 3

Returns -1 if element is not found.

notes.lastIndexOf('fa');  // -1


int lastIndexOf(E element, [int? start]);