Use of the extract method operation programatically

Hello,

I try to use the refactoring operation programatically but I receive always the followinf exception:

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[  17535]  ERROR - com.intellij.ide.IdeEventQueue - Error during dispatching of java.awt.event.MouseEvent[MOUSE_RELEASED,(330,54),absolute(785,78),button=1,modifiers=Button1,clickCount=1] on frame0
java.lang.NullPointerException  at com.intellij.refactoring.extractMethod.ExtractMethodProcessor.doRefactoring(ExtractMethodProcessor.java:525)

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The code I defined to perform this operation is:

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PsiElement[] elements = method.getBody().getStatements()[0].getChildren();// method is the method from which I like to extract the new method.

ExtractMethodProcessor extractMethodProcessor = new ExtractMethodProcessor(project, editor,elements,null,"accept",method.getName(),HelpID.EXTRACT_METHOD);

extractMethodProcessor.doRefactoring();


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Is there one who could know what is wrong here or is there a person who used this operation before?


Thanks