private boolean dataEquals( Arc otherArc )
	{
		char[] data1 = getData();
		char[] data2 = otherArc.getData();
		if ( (data1==null&&data2!=null)||(data1!=null&&data2==null) )
			return false;
		else if ( data1==null&&data2==null)
			return true;
		else if ( data1.length != data2.length )
			return false;
		else
		{
			for ( int i=0;i<data1.length;i++ )
				if ( data1[i] != data2[i] )
					return false;
		}
		return true;
	}