java.nio.file.Path implements Iterable<Path>, and provides an iterator over the name elements of the path. Declaring a parameter of type Iterable<Path> is not recommended, since it allows clients to pass either an Iterable of Paths, or a single Path. Using Collection<Path> prevents clients from accidentally passing a single Path.

Example:

void printPaths(Iterable<Path> paths) {
  for (Path path : paths) System.err.println(path);
}

printPaths(Paths.get("/tmp/hello"));
tmp
hello

printPaths(ImmutableList.of(Paths.get("/tmp/hello")));
/tmp/hello