If i change this method:  public void setCustom(Map&lt;String, Object&gt; custom) {     this.custom = (LinkedHashMap&lt;String, Object&gt;)custom; }   to:  public void setCustom(LinkedHashMap&lt;String, Object&gt; custom) {     this.custom = custom; }   do i have to update the serialVersionUID? Is it a compatible change or not?
Eclipse issues warnings when a serialVersionUID is missing.       The serializable class Foo does not declare a static final   serialVersionUID field of type long   What is serialVersionUID and why is it important?  Please show an example where missing serialVersionUID will cause a problem.
How To Recover My Data From Not Detected Hard Disk? I am using Acer Laptop one day before my Hard Disk is not detected in BIOS and not booting it's shows Insert Boot Disk and I am try another H.D.D it's boot perfectly in my Laptop but,I want detect and recover my data on not detected hard disk. I am not experience about Hard Disk please, can any one help me how to recover my data from not detected Hard Disk. From what items can a wizard learn his spells? I'm now wondering after googling for a while, what are the different sources a Wizard can learn his spells from? Is it only limited to scrolls and tomes, or can a Wizard learn spells from other magic items?  The following quotes are from the PHB, page 114 Your spellbook      You might find other spells during your adventures. You could discover a spell recorded on a scroll in an evil wizard's chest, for example, or in a dusty tome in an ancient library.      Copying a Spell into the Book   When you find a wizard spell of 1st level or higher, you can add it to your spellbook if it is of a level for which you have spell slots and if you can spare the time to decipher and copy it.      For each level of the spell, the process takes 2 hours and costs 50gp. The costs represents material components you expend as you experiment with the spell to master it, as well as the fine inks you need to record it. Once you have spent this time and money, you can prepare the spell just like your other spells.   The way this is worded and considering the few examples we're given, shouldn't it be possible to learn a spell from more than just written sources?  An example would be Wand of Magic Missile: would it be possible for a Wizard to learn the spell Magic Missile by studying the spell when used by the item and write down his research and thus learning how to use the spell on his own and eventually master it? How can I find the unit vector of a three dimensional vector? For example, I have a problem that I am working on that tells me that I have a vector $\hat{r}$ that is a unit vector, and I am told to prove this fact:     $\hat{r} = \frac{2}{3}\hat{i} - \frac{1}{3}\hat{j} - \frac{2}{3}\hat{k}$   I know that with a two-dimension unit vector that you can split it up into components, treat it as a right-triangle, and find the hypotenuse. Following that idea, I tried something like this, where I found the magnitude of the vectors $\hat{i}$ and $\hat{j}$, then using that vector, found the magnitude between ${\hat{v}}_{ij}$ and $\hat{k}$:     $\left|\hat{r}\right| = \sqrt{\sqrt{{\left(\frac{2}{3}\right)}^{2} + {\left(\frac{-1}{3}\right)}^{2}} + {\left(\frac{-2}{3}\right)}^{2}}$   However, this does not prove that I was working with a unit vector, as the answer did not evaluate to one. How can I find the unit vector of a three-dimensional vector?  Thank you for your time. Can inner classes access private variables? class Outer {      class Inner {     public:         Inner() {}         void func() ;     };  private:     static const char* const MYCONST;     int var; };  void Outer::Inner::func() {     var = 1; }  const char* const Outer::MYCONST = "myconst";   This errors out when I compile with class Outer::Inner' has no member named `var' Using OpenSUSE leap 15.1 10.2.29-lp151.2.9.1-x86_64 from vendor OpenSUSE (installed)  CREATE TABLE testtab2(     my_id2 INT AUTO_INCREMENT,     name2 VARCHAR(10),     comment2 VARCHAR(20),     PRIMARY KEY (my_id2) );   testtab.txt:  |Roger |hurray   | |George|today    | |Paul  |yesterday| |John  |last year| |Ringo |tomorrow |   LOAD DATA LOCAL INFILE 'testtab.txt' INTO TABLE testtab FIELDS TERMINATED BY '|';   works fine with linenumbers (my_id) 1-5  INSERT INTO testtab (name,comment) VALUES ('Beatles','band');   this gets linenumber (my_id) 8 - should be 6.  If testtab.txt have 8 records and using INSERT INTO 1 record this gets linenr (my_id) 16. This happens in other tables too - one moved from 199 to 256.  Anyone who can solve the problem? How can I convert audio from MP4 or FLV video files to mp3? Is there an application that allows me to extract the audio from a MP4 or FLV video file and store it as an MP3 file for use in a portable media player? I'm moving all files to a new computer, via an external hard drive. I am certain that broken links will be a concern. What can I do to fix this? Is there a 'Best Practices' kind of way to prevent this problem beforehand? I have many hundreds of .blend files, and of course, I fear losing them. Who knows about the summation of this series: $$\sum\limits_{i=1}^{n}i^m $$  where $m$ is constant and $m\in \mathbb{N}$?  thanks How to prevent a coauthor from stealing the article? Please go through the following incidents to understand the problem.  Mr. A is a Ph.D. student of some institute who was working with Prof. B of another institute on a very interesting mathematical problem since last three years. Recently, they came across a significant solution to it. They wrote a research article to publish in a very good mathematics journal that accepts the online submission.  Prof. B wanted to submit it to the journal by himself. Mr. A agreed.   A few days ago, Mr. A wanted to know about the submission of their article via telephone. Prof. B informed that the article is submitted. But, Mr. A received any confirmation e-mail neither from the journal nor Prof. B forwarded the submission mail to him. Prof. B did not upload it in arXiv, which is a free preprint repository.  Mathematics journals used to take a long duration to review and publish an article. Prof. B told that submitting this article to arXiv will immediately attract community attention. Many researchers will start working in the new direction. As a result, Mr. A and Prof. B may lose their opportunity to work on that problems. Also, the article may be stolen.  Mr. A did not ask Prof. B to forward the submission confirmation mail to him. Prof. might think that Mr. A is suspecting him. It may affect the relationship. Also, Prof. is a very powerful person in the administration, who may prevent an opportunity for Mr. A to gain a job. Again from some of his friends, Mr. A came to know that Prof. had distributed related research problems to his collaborators.  As a consequence, Mr. A is thinking that Prof. has submitted this work in his own name and he has lost his credit as the first author of this article.  Now the question is: How Mr. A may save his credit and his work without hampering his relationship with Prof B? I have a map of a city and a .csv-file containing 700 geographic coordinates pointing to locations within that city.  How can I plot these 700 locations on the map? How to get product recommendations Possible Duplicate:          I have a question of the form "what companies provide service X?"  I checked meta, and apparently such questions are highly discouraged on all Stack Exchange sites. Which is fine, but it obviously raises the meta-question: Where can I ask my question?  (In particular, I know that there are people hanging out on Stack Overflow who have probably needed the same service, so if an answer exists, they possess it...)  Edit: I should perhaps point out that the service I'm looking for is rather specific and slightly obscure. Otherwise, yeah, this would be a 10-second exercise with Google. Why there isn't any integer solutions in non-zero integers for $z^3 = 3(x^3 +y^3+2xyz)$? Consider the following Diophantine equation  $$z^3 = 3(x^3 +y^3+2xyz)$$  Is there any elementary proof for the non-solubility in non-zero integers for this  Diophantine equation, where the absolute value of $x, y$ and $z$ are pairwise coprime integers?  I have proved the impossibility of solution of this Diophantine equation in non-zero integers, but that took quite a few pages and I consider this too long. I hope for a much more elementary and shorter proof for this puzzle.  Hint: It should be noted that is also true for the non-availability of the similar form (replacing coefficient 3 by 1) as the following:   $$z^3=x^3+y^3+2xyz,$$ but this case is very simple to prove, where $x, y\;\&amp;\; z$ are nonzero integers. Sometimes a suggested edit is  because of a concurrent direct edit that takes precedence.  Since this is no fault of the edit suggestor, such rejections should not count against the suggestor when counting .  Here are some examples where it happened: Finding specific users by their location and a tag score How to install apk in 2nd user of android 5.0 without playstore So, android 5.0.2 doesn't allow side loading of apks for 2nd user (irrespective of whether it is guest or standard user). "Unknown Sources" is disabled and is uncheckable. And I use a pure Cyanogen Mod 12 (android 5.0.2) without any Google apps. So, there is no Play Store app.  But I have root access.  As shown in the pics, Unknown Sources is Uncheckable and installation is blocked.  (Click image to enlarge)     With this situation, how can i install apks on to the 2nd user account??  EDIT:   It seems Google intentionally (in the name of security) blocked sideloading apks for 2nd user in android 5.0.2. There is a bug report . And sideloading was reenabled in android 5.1.   I will post how to sideload apks on lolipop 2nd user using adb. If this can be done without adb please post. Remove line containing certain string and the following line Proof verification: Set of partial limits of a sequence is closed Zero vector of a vector space I know that every vector space needs to contain a zero vector. But all the vector spaces I've seen have the zero vector actually being zero (e.g. $\mathbf{0}=\langle0,0,\ldots,0\rangle$). Can't the "zero vector" not involve zero, as long as it acts as the additive identity? If that's the case then are there any graphical representations of a vector space that does not contain the origin? Custom ordering of duplicate targets is not necessarily honored on mobile apps Connect two computers with SSH in a home LAN I have two ubuntu computer shared the same wifi and desire to reach another from one's terminal.  First create an user on the second computer named "Second" and hostname "Algorithms"    Then tried to reach it from the other with SSH,  but get error report as   $ ssh second@Algorithms   ssh: Could not resolve hostname algorithms: nodename nor servname provided, or not known   The solution I tried is based on   What's the problem with my experiment?