user/test/com/google/gwt/resources/client/gss/lenientExternal.gss

@external nonObfuscated;

/* will be considered as outside the conditional */
/* Compiler fails when lenient mode is disable */
@if (eval("com.google.gwt.resources.client.gss.BooleanEval.FIRST")) {
  @external nonObfuscated2;
}

@if (is("customProperty", "true")) {
  @external nonObfuscated3;
}

@if (!is("customProperty", "true")) {
  @external obfuscated;
}

.obfuscated,
.nonObfuscated,
.nonObfuscated2,
.nonObfuscated3{
  color: white;
}