ConcurrentModificationException with 2 Iterators and one ArrayList
Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop
I can't see my background image in the 3D view I try to set up an image as background for a basic blender tutorial, but it isn't visible.  This is the image I try to have as background: I'm trying to enable alsa on different prefix than default through winetricks.  More specifically, the prefix that has Rosetta Stone on it, as it cannot see my microphone.  When I open winetricks, it only lets me select default.  I tried anyway, on default, and it did not resolve the issue.  I saw some answers online, through the terminal, but that didn't work either.  Maybe I have the syntax wrong?  steve@stevelap:~$ WINEPREFIX=~/.PlayOnLinux/wineprefix/Rosetta sh winetricks alsa sh: 0: Can't open winetricks steve@stevelap:~$ sudo WINEPREFIX=~/.PlayOnLinux/wineprefix/Rosetta sh winetricks alsa [sudo] password for steve:  sh: 0: Can't open winetricks   Could anyone please offer assistance?  Thanks! Show that:  If $U$ is a principal ultrafilter, then the canonical inmersion $j$ is an isomorphism between $\mathcal A$ and $Ult_{U}\mathcal A$ How to use GeoPandas buffer function to get buffer zones in kilometers? Are confidence intervals open or closed intervals? Particular nodes are missing from node editor I am looking for the  but it is not available under the Vector nodes menu or any other menu. I have Blender 2.77 which cooresponds with the manual version in the above link.    I also cannot find the Texture Coordinate or Gradient Texture.  Likely I am doing something wrong. What level is a spell if you cast it without expending a spell slot? There are ways to cast spells without expending a spell slot such as:  Master Transmuter (PHB 119):     Restore Life. You cast the raise dead spell on a creature you touch   with the transmuter’s stone, without expending a spell slot or needing   to have the spell in your spellbook.   Armor of Shadows (PHB 110):     You can cast mage armor on yourself at will, without expending a spell slot or material components.   Whispers of the Grave (PHB 111):     You can cast speak with dead at will, without expending a spell   slot.   See also: Channel Divinity: Read Thoughts (PHB 59-60), Mystic Arcanum (PHB 108), Beast Speech (PHB 110), Chains of Carceri (PHB 110), Eldritch Sight (PHB 110), Fiendish Vigor (PHB 111), Mask of Many Faces (PHB 111), Master of Myriad Forms (PHB 111), Misty Visions (PHB 111), Otherwordly Leap (PHB 111), Signature Spells (PHB 115), Spell Mastery (PHB 115), Shapechanger (PHB 119), Boon of Spell Mastery (DMG 232) and Boon of Spell Recall (DMG 232).  What level are these spells if you cast them without expending a spell slot? Recently the cranks on my bike started to creak. I checked with my usual "bike-bible" . They recommended dis-assemble, lubricate, re-assemble.  So I did that.  Remove cranks. Remove spindle. Clean. Lubricate. Reassemble.  No, the creak is still there.  (To find out the source-area of the sound I had a friend riding the bike slowly while I ran alongside listening. And the sound where coming from the area of the bottom bracket/cranks. I am happy no neighbor saw me...)   For each revelation of the cranks there are two creak-noises.  If I, when on the bike, push down with both feet I hear a noise. Turn 180 degrees without pressure, push down again and there is the noise again. If I am "too soft", low pressure there are no sound. Since I have clips I have tried to only work with one foot to keep a constant load during a revelation, there where no detectable sound then.  Anyone have any idea what is wrong on the bike? And how I should fix it?  /Leif There is a way to use my Galaxy tab s like a wacom table, on linux? How do I enable hardware virtualization technology (VT-x) for use in Virtualbox? So I am trying to run Ubuntu in a virtualbox but on installing 12.10 from the .iso I was greeted by a warning telling me that audio wouldn't work then I pressed next and this popped up:  Failed to open a session for the virtual machine Tux 3 VT-x features locked or unavailable in MSR (VERR_VMX_MSR_LOCKED_OR_DISABLED) Details  Result Code:  E_FAIL (0x80004005) Component:  Console Interface:  IConsole {db7ab4ca-2a3f-4183-9243-c1208da92392}   And then it doesn't work.  I assigned 4GB of my 8GB to Ubuntu, 100 dynamically allocated GB of space, and 12MB of graphics memory. I'm running an Asus p8z77 V LX mobo with an Intel i5 3550 processor.   Downloaded 12.04.2 on my PC and tried again. Still getting the same message. Is it possible to match encrypted documents using user-defined search terms? Suppose I am storing a number of encrypted documents in a database. I would like to make it possible to identify the subset of documents whose contents match user-specified search terms without a) maintaining a plaintext index or b) decrypting documents on the fly. Is there any way to accomplish this securely?  By the same token, I'm wondering if a collection of encrypted documents can be sorted according to an encrypted attribute (e.g., document title) without first decrypting all attribute values. I am dissecting some code and came across this,   $sql = 'SELECT page.*, author.name AS author, updator.name AS updator '      . 'FROM '.TABLE_PREFIX.'page AS page '      . 'LEFT JOIN '.TABLE_PREFIX.'user AS author ON author.id = page.created_by_id '      . 'LEFT JOIN '.TABLE_PREFIX.'user AS updator ON updator.id = page.updated_by_id '      . 'WHERE slug = ? AND parent_id = ? AND (status_id='.Page::STATUS_REVIEWED.' OR status_id='.Page::STATUS_PUBLISHED.' OR status_id='.Page::STATUS_HIDDEN.')';   I am wondering what the "?" does in the WHERE statement.  Is it some sort of parameter holder? Why do only two sexes exist for animals? I've always heard this reasoning, and it makes obvious sense, but how do you actually show it for some arbitrary product? Would it be something like this?  $$(a(b(cd)))e=((ab)(cd))e=(((ab)c)d)e=abcde?$$  Do you just say that the grouping of the parentheses now corresponds to just multiplying straight through? Thanks. Why are processes in Windows 8 32 bit? So in the documentation for the DescribeFieldResult.getDefaultValue , it says:     Returns the default value for this field   There is a related method called getDefaultValueFormula whose description reads:     Returns the default value specified for this field if a formula is not used.   What is the difference between these methods? I have a field with a default value. When I call getDefaultValue, I get null. When I call getDefaultValueFormula, I get back "This is the default value" (with quotes). I don't understand why getDefaultValue returns null. I'm having a lot of trouble figuring this one out.  Determine if  $\sum_{i=2}^{\infty} \frac{(-1)^n}{n+(-1)^n}$ converges or diverges  Both ratio and root test are inconclusive and I'm at a loss. Can anyone help me? EDIT: As of Java 8, static methods are now allowed in interfaces.  Here's the example:  public interface IXMLizable&lt;T&gt; {   static T newInstanceFromXML(Element e);   Element toXMLElement(); }   Of course this won't work.  But why not?  One of the possible issues would be, what happens when you call:  IXMLizable.newInstanceFromXML(e);   In this case, I think it should just call an empty method (i.e. {}).  All subclasses would be forced to implement the static method, so they'd all be fine when calling the static method.  So why isn't this possible?  EDIT: I guess I'm looking for answer that's deeper than "because that's the way Java is".   Is there a particular technological reason why static methods can't be overwritten? That is, why did the designers of Java decide to make instance methods overrideable but not static methods?  EDIT: The problem with my design is I'm trying to use interfaces to enforce a coding convention.  That is, the goal of the interface is twofold:   I want the IXMLizable interface to allow me to convert classes that implement it to XML elements (using polymorphism, works fine). If someone wants to make a new instance of a class that implements the IXMLizable interface, they will always know that there will be a newInstanceFromXML(Element e) static constructor.   Is there any other way to ensure this, other than just putting a comment in the interface? ASP.NET MVC How to pass JSON object from View to Controller as Parameter I have a complex JSON object which is sent to the View without any issues (as shown below) but I cannot work out how Serialize this data back to a .NET object when it is passed back to the controller through an AJAX call. Details of the various parts are below.     var ObjectA = {         "Name": 1,         "Starting": new Date(1221644506800),          "Timeline": [             {                 "StartTime": new Date(1221644506800),                 "GoesFor": 200              }             ,             {                 "StartTime": new Date(1221644506800),                 "GoesFor": 100              }          ]     };   I am not sure how this object can be passed to a Controller Method, I have this method below where the Timelines object mirrors the above JS object using Properties.  public JsonResult Save(Timelines person)   The jQuery I am using is:          var encoded = $.toJSON(SessionSchedule);          $.ajax({             url: "/Timeline/Save",             type: "POST",             dataType: 'json',             data: encoded,             contentType: "application/json; charset=utf-8",             beforeSend: function() { $("#saveStatus").html("Saving").show(); },             success: function(result) {                 alert(result.Result);                 $("#saveStatus").html(result.Result).show();             }         });   I have seen this question which is similar, but not quite the same as I am not using a forms to manipulate the data.   I have also seen references to using a 'JsonFilter' to manually deserialize the JSON, but was wondering if there is a way to do it nativly though ASP.NET MVC? Or what are the best practices for passing data in this way? is $\sqrt{x}$ always positive?