public function setNumberOfMandatoryArguments( $number = 0 )
	{
		if( !is_int( $number ) )														//  no Integer given
			throw new InvalidArgument( 'No integer given' );							//  throw Exception
		if( $number === $this->numberArguments )										//  this Number is already set
			return FALSE;																//  do nothing
		$this->numberArguments	= $number;												//  set new Argument Number
		return TRUE;																	//  indicate Success
	}