removeFirstOccurrence method
Returns a copy of this list where the first occurrence of element
is
removed from if present.
If element
is not present in the list, the list is returned unchanged.
Use remove to remove all occurrences of a value.
Implementation
ImmortalList<T> removeFirstOccurrence(Object? element) =>
_mutateAsListIf(contains(element), (list) => list..remove(element));