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

@external externalClass, externalWithoutMethod, "unobfuscated*";

@if (is("test.property", "true")) {
  @external externalClass2;
}
@else {
  @external obfuscatedClass;
}

.obfuscatedClass {
  width: 100%;
}

.externalClass {
  height: 50px;
}

.externalClass2 {
  height: 50px;
}

.unobfuscated {
  height: 50px;
}

.unobfuscated-with-prefix-without-method {
  width: 15px;
}

.unobfuscated2 {
  height: 50px;
}

.externalWithoutMethod {
  color: white;
}

/* will be evaluated to false, shouldn't throw an error*/
@if (!is("test.property", "true")) {
  @external class-without-method;
  .class-without-method{
    display: inline-block;
  }
}