### Question:
CardHolder implements Cloneable, Serializable, Loggeable { public String getBIN () { return pan.substring(0, BINLEN); } CardHolder();  CardHolder(String track2);  CardHolder(String pan, String exp);  CardHolder(ISOMsg m); void parseTrack2(String s); void setTrack1(String track1); String getTrack1(); boolean hasTrack1(); String getNameOnCard(); String getTrack2(); boolean hasTrack2(); void setSecurityCode(String securityCode); String getSecurityCode(); boolean hasSecurityCode(); @SuppressWarnings("unused") String getTrailler(); @SuppressWarnings("unused") void setTrailler(String trailer); String getTrailer(); void setTrailer(String trailer); void setPAN(String pan); String getPAN(); String getBIN(); void setEXP(String exp); String getEXP(); boolean isExpired(); boolean isExpired(Date currentDate); boolean isValidCRC(); static boolean isValidCRC(String p); void dump(PrintStream p, String indent); String getServiceCode(); boolean seemsManualEntry(); @Override int hashCode(); @Override boolean equals(Object obj);  }### Answer:
@Test public void testGetBIN() throws Throwable { CardHolder cardHolder = new CardHolder(); cardHolder.setPAN("testCardHolderPan"); String result = cardHolder.getBIN(); assertEquals("testCa", result, "result"); }
@Test public void testGetBINThrowsNullPointerException() throws Throwable { try { new CardHolder().getBIN(); fail("Expected NullPointerException to be thrown"); } catch (NullPointerException ex) { if (isJavaVersionAtMost(JAVA_14)) { assertNull(ex.getMessage(), "ex.getMessage()"); } else { assertEquals("Cannot invoke \"String.substring(int, int)\" because \"this.pan\" is null", ex.getMessage(), "ex.getMessage()"); } } }