Expose methods to test code but not to end-users?

Given:

public class Dummy
{   
  /**
   * Constructor meant to be used for test code.
   * @param scope test-specific "globals"
   * @param value some user-supplied value
   */
  public Dummy(SingletonScope scope, int value)
  {
    // ...
  }

  /**
   * Constructor meant to be used by end-users.
   * @param value some user-supplied value
   */
  public Dummy(int value)
  {
    scope = someDefaultValue();
    // ...
  }
}

Is there a design pattern that will allow me to expose the first method to test classes that are scattered across multiple packages, and the second method to end-users?

I don't want to expose the first constructor to end-users because it clutters the API specification and I don't want it to form a de-facto standard (similar to sun.misc.Unsafe). The solution cannot use dependency injection or reflection.