public function readString()
	{
		if( !$this->exists( $this->fileName ) )
			throw new RuntimeException( 'File "'.$this->fileName.'" is not existing' );
		if( !$this->isReadable( $this->fileName ) )
			throw new RuntimeException( 'File "'.$this->fileName.'" is not readable' );
		return file_get_contents( $this->fileName );
	}