public function childAtIndex( $index ) {
		if( $index !== null && isset($this->childElements[$index]) ) {
			return $this->childElements[$index];
		}

		return null;
	}
public function childAtIndex( $index ) {
		if( $index !== null && isset($this->childElements[$index]) ) {
			return $this->childElements[$index];
		}

		return null;
	}
public function childAtIndex ( $ index ) { if ( $ index !== null && isset ( $ this -> childElements [ $ index ] ) ) { return $ this -> childElements [ $ index ] ; } return null ; }
Gets the child element at a given index or null if not found.

@param int $index
@return AbstractElement|null
Gets the child element at a given index or null if not found .