### Question:
AbstractToken implements Token { @Nullable @Override public Instant getNotBefore() { return tokenBody.contains(NOT_BEFORE) ? tokenBody.getAsInstant(NOT_BEFORE) : tokenBody.getAsInstant(ISSUED_AT); } AbstractToken(@Nonnull DecodedJwt decodedJwt);  AbstractToken(@Nonnull String jwtToken); @Nullable @Override String getHeaderParameterAsString(@Nonnull String headerName); @Override boolean hasClaim(@Nonnull String claimName); @Override boolean hasHeaderParameter(@Nonnull String parameterName); @Nullable @Override String getClaimAsString(@Nonnull String claimName); @Nullable @Override List<String> getClaimAsStringList(@Nonnull String claimName); @Nullable @Override JsonObject getClaimAsJsonObject(String claimName); @Nullable @Override Instant getExpiration(); @Override boolean isExpired(); @Nullable @Override Instant getNotBefore(); @Override String getTokenValue(); @Override Set<String> getAudiences(); @Override boolean equals(Object o); @Override int hashCode(); @Override String getZoneId(); @Override String toString();  }### Answer:
@Test public void getNotBefore_notContained_shouldBeNull() { assertThat(String.valueOf(cut.getNotBefore().toEpochMilli())).startsWith("1572017569"); }