### Question:
UIMessageSource extends UIComponentBase { public void setPrefix(String prefix) { getStateHelper().put(PropertyKeys.prefix, prefix); }  @Override String getFamily(); @Override void setParent(UIComponent parent); String getVar(); void setVar(String var); MessageSource getSource(); void setSource(MessageSource source); String getPrefix(); void setPrefix(String prefix); boolean isReturnStringsWhenPossible(); void setReturnStringsWhenPossible(boolean returnStringsWhenPossible); boolean isPrefixOptional(); void setPrefixOptional(boolean prefixOptional); static final String COMPONENT_FAMILY; }### Answer:
@Test public void shouldSupportDefinedPrefixes() throws Exception { this.uiMessageSource.setPrefix("a.b,a.b.c , a.b.c.d"); assertCodes("z", new String[] { "a.b.z", "a.b.c.z", "a.b.c.d.z" }); }