WP_Filesystem_Direct::move( string $source, string $destination, bool $overwrite = false )

	public function move($source, $destination, $overwrite = false) {
		if ( ! $overwrite && $this->exists($destination) )
			return false;

		// Try using rename first. if that fails (for example, source is read only) try copy.
		if ( @rename($source, $destination) )
			return true;

		if ( $this->copy($source, $destination, $overwrite) && $this->exists($destination) ) {
			$this->delete($source);
			return true;
		} else {
			return false;
		}
	}