code: protected PaasEntityDriver doInitDriver(CloudFoundryPaasLocation location) {
          if (driver != null) {
              if (location.equals(driver.getLocation())) {
                  return driver; //just reuse
              } else {
                  log.warn("driver/location change is untested for {} at {}; " +
                          "changing driver and continuing", this, location);
                  return newDriver(location);
              }
          } else {
              return newDriver(location);
          }
      }
docs: Creates the driver (if does not already exist or needs replaced for some reason).
  Returns either the existing driver
  or a new driver. Must not return null.