BuilderWithDeprecatedField () { java.util.List<String> xyzs; switch (this.xyzs == null ? 0 : this.xyzs.size()) { case 0: xyzs = java.util.Collections.emptyList(); break; case 1: xyzs = java.util.Collections.singletonList(this.xyzs.get(0)); break; default: xyzs = java.util.Collections.unmodifiableList(new java.util.ArrayList<String>(this.xyzs)); } return new BuilderWithDeprecatedField(this.bar, this.foo, xyzs); }