code: function deleteAttribute($attr, $compare = 'total', $case_sensitive = false) {
  		$f = $this->findAttribute($attr, $compare, $case_sensitive);
  		if (is_array($f) && $f) {
  			foreach($f as $a) {
  				unset($this->attributes[$a[2]]);
  				if ($this->attributes_ns !== null) {
  					unset($this->attributes_ns[$a[1]]);
  				}
  			}
  		}
  	}
docs: Delete attribute(s)
  @param string|int $attr Negative int to count from end
  @param string $compare Find node using "namespace", "name" or "total"
  @param bool $case_sensitive Compare with case sensitivity