@Nullable
  <T extends PsiExpression> T getSingleExpression(Class<T> wantedType) {
    PsiStatement statement = getSingleStatement();
    if(statement instanceof PsiExpressionStatement) {
      PsiExpression expression = ((PsiExpressionStatement)statement).getExpression();
      return tryCast(expression, wantedType);
    }
    return null;
  }
@Nullable
  <T extends PsiExpression> T getSingleExpression(Class<T> wantedType)