### Question:
GdsEdition { public boolean isInvalidLicense() { return get() == State.INVALID_LICENSE; } private  GdsEdition(); static GdsEdition instance(); boolean isOnEnterpriseEdition(); boolean isOnCommunityEdition(); boolean isInvalidLicense(); Optional<String> errorMessage(); void setToEnterpriseEdition(); void setToCommunityEdition(); void setToInvalidLicense(String errorMessage);  }### Answer:
@Test void isInvalidLicense() { GdsEdition.instance().setToInvalidLicense("foobar"); assertEquals("foobar", GdsEdition.instance().errorMessage().get()); assertTrue(GdsEdition.instance().isInvalidLicense()); assertFalse(GdsEdition.instance().isOnEnterpriseEdition()); assertFalse(GdsEdition.instance().isOnCommunityEdition()); }