code: public InputStream execute()
          throws EFapsException
      {
          final boolean hasAccess = super.getInstance().getType().hasAccess(super.getInstance(),
                                                                            AccessTypeEnums.CHECKOUT.getAccessType());
          if (!hasAccess) {
              throw new EFapsException(this.getClass(), "execute.NoAccess");
          }
          return this.executeWithoutAccessCheck();
      }
docs: Executes the checkout and returns an input stream by calling method
  {@link #executeWithoutAccessCheck()}.
  
  @return input stream of the checked in file
  @throws EFapsException if the current context user has now access to
  checkout the file out of the eFaps object
  @see #executeWithoutAccessCheck()