Remove always true/false occurrences

Author: alexandre-daubois

Finder.php

@@ -699,24 +699,20 @@ public function getIterator(): \Iterator
  * The set can be another Finder, an Iterator, an IteratorAggregate, or even a plain array.
  *
  * @return $this
- *
- * @throws \InvalidArgumentException when the given argument is not iterable
  */
  public function append(iterable $iterator): static
  {
  if ($iterator instanceof \IteratorAggregate) {
  $this->iterators[] = $iterator->getIterator();
  } elseif ($iterator instanceof \Iterator) {
  $this->iterators[] = $iterator;
- } elseif (is_iterable($iterator)) {
+ } else {
  $it = new \ArrayIterator();
  foreach ($iterator as $file) {
  $file = $file instanceof \SplFileInfo ? $file : new \SplFileInfo($file);
  $it[$file->getPathname()] = $file;
  }
  $this->iterators[] = $it;
- } else {
- throw new \InvalidArgumentException('Finder::append() method wrong argument type.');
  }
 
  return $this;