public PyStatement fun(String self_name) {
   if (PyNames.CANONICAL_SELF.equals(self_name)) {
     return (PyStatement) myDeclaration;
   }
   final String text = myDeclaration.getText();
   final Project project = myDeclaration.getProject();
   return PyElementGenerator.getInstance(project)
       .createFromText(
           LanguageLevel.getDefault(),
           PyStatement.class,
           text.replaceFirst(PyNames.CANONICAL_SELF + "\\.", self_name + "."));
 }
 private void addToExistingImport(PyImportElement src) {
   final PyElementGenerator gen = PyElementGenerator.getInstance(myTarget.getProject());
   // did user choose 'import' or 'from import'?
   PsiElement parent = src.getParent();
   if (parent instanceof PyFromImportStatement) {
     // add another import element right after the one we got
     PsiElement newImportElement = gen.createImportElement(LanguageLevel.getDefault(), myName);
     parent.add(newImportElement);
   } else { // just 'import'
     // all we need is to qualify our target
     myTarget.replace(
         gen.createExpressionFromText(
             LanguageLevel.forElement(myTarget), src.getVisibleName() + "." + myName));
   }
 }
 @Nullable
 private static PsiElement addFieldToSetUp(
     PyClass clazz, final Function<String, PyStatement> callback) {
   final PyFunction init =
       clazz.findMethodByName(PythonUnitTestUtil.TESTCASE_SETUP_NAME, false, null);
   if (init != null) {
     return AddFieldQuickFix.appendToMethod(init, callback);
   }
   final PyFunctionBuilder builder =
       new PyFunctionBuilder(PythonUnitTestUtil.TESTCASE_SETUP_NAME, clazz);
   builder.parameter(PyNames.CANONICAL_SELF);
   PyFunction setUp = builder.buildFunction(clazz.getProject(), LanguageLevel.getDefault());
   final PyStatementList statements = clazz.getStatementList();
   final PsiElement anchor = statements.getFirstChild();
   setUp = (PyFunction) statements.addBefore(setUp, anchor);
   return AddFieldQuickFix.appendToMethod(setUp, callback);
 }