private void assignManagerField(final Object target, final Field field)
      throws IllegalAccessException {
    throwIfNotSameType(field, VM.class);

    field.setAccessible(true);
    if (field.getType().isArray()) {
      field.set(target, managers);
    } else {
      field.set(target, managers[0]);
    }
  }
Note: Overriding MethodRule is only way to get {@code Object target}
geode-core/src/distributedTest/java/org/apache/geode/management/ManagementTestRule.java