### Question:
ZkClientConfiguration implements Serializable { public void setConnectionStr(final String connectionStr) { Preconditions.checkArgument(connectionStr.length() > 0, "Zookeeper connection string needs to be set"); this.connectionStr = connectionStr; } ZkClientConfiguration();  ZkClientConfiguration(final ZkClientConfiguration other); static ZkClientConfiguration from(Configuration config); String getConnectionStr(); void setConnectionStr(final String connectionStr); int getSessionTimeout(); void setSessionTimeout(final int sessionTimeout); int getConnectionTimeout(); void setConnectionTimeout(final int connectionTimeout); int getReconnectionDelay(); void setReconnectionDelay(final int reconnectionDelay); int getTerminationTimeout(); void setTerminationTimeout(final int terminationTimeout); @Override int hashCode(); @Override boolean equals(final Object obj); @Override String toString(); static final String CONNECTION_STRING; static final String CONNECTION_STRING_DEFAULT; static final String SESSION_TIMEOUT; static final int SESSION_TIMEOUT_DEFAULT; static final String CONNECTION_TIMEOUT; static final int CONNECTION_TIMEOUT_DEFAULT; static final String RECONNECTION_DELAY; static final int RECONNECTION_DELAY_DEFAULT; static final String TERMINATION_TIMEOUT; static final int TERMINATION_TIMEOUT_DEFAULT; }### Answer:
@Test(expected = IllegalArgumentException.class) public void testInvalidConnectionStr() { new ZkClientConfiguration().setConnectionStr(StringUtils.EMPTY); }