### Question:
Domain extends BaseEntity { public Boolean getBooleanAttribute(final String attributeName) { return getBooleanAttribute(attributeName, null); } Domain();  Domain(final String name, final int type);  Domain(final String name, final int type, final String serverHost); String getName(); void setName(final String name); int getType(); void setType(final int type); String getServerHost(); void setServerHost(final String serverHost); String getMemberPath(); void setMemberPath(final String memberPath); UsernameConfiguration getUsernameConfiguration(); void setUsernameConfiguration(
			final UsernameConfiguration usernameConfiguration); Map<String, String> getConfiguration(); void setConfiguration(final Map<String, String> configuration); DomainRuntime getRuntime(); void setRuntime(final DomainRuntime runtime); String getIdentifierPrefix(); String getIdentifierSuffix(); String getAttribute(final String attributeName); String getAttribute(final String attributeName,
			final String defaultValue); Boolean getBooleanAttribute(final String attributeName); Boolean getBooleanAttribute(final String attributeName,
			final Boolean defaultValue); int getIntAttribute(final String attributeName); @Override int hashCode(); @Override boolean equals(final Object obj); @Override String toString(); static final int TYPE_SUBDOMAIN; static final int TYPE_SUBDIRECTORY; }### Answer:
@Test public void testGetBooleanAttribute() { Boolean nonexistent = domain.getBooleanAttribute("nonexistent"); assertNull(nonexistent); Boolean defaultValue = domain.getBooleanAttribute("nonexistent", Boolean.TRUE); assertTrue(defaultValue.booleanValue()); Map<String, String> configuration = new HashMap<String, String>(); domain.setConfiguration(configuration); nonexistent = domain.getBooleanAttribute("nonexistent"); assertNull(nonexistent); }