### Question:
CertificateManager { public Certificate[] getCerts() { return certs; } CertificateManager(KeyStoreLoader loader); void setPasswordRequestListener(KeyStoreEntryPasswordRequestListener passwordRequestListener); void setKeyStoreRequestListener(KeyStoreRequestListener keyStoreRequestListener); Certificate[] getCerts(); boolean hasNoCertificates(); byte[] sign(Certificate cert, byte[] challenge); Signature extractSignature(Certificate cert); boolean verify(Certificate cert, byte[] original, byte[] signed); void load();  }### Answer:
@Test public void testGetCerts_HasExpectedNumberOfCerts() { Certificate[] certs = manager.getCerts(); int numCerts = certs.length; assertThat(numCerts, equalTo(1)); }