title: Referencing a enum defined in another proto
body: <p>In <code>A.proto</code>, I defined an enum called <code>Foo</code>. Then in  <code>B.proto</code>, I referenced this enum as:</p>
  <pre><code>message Bar {
      .pathofA.Foo foo = 1;
  }
  </code></pre>
  <p>Notice that  <code>A.proto</code> does not have a go_proto_library declared. It's only in java. While <code>B.proto</code> has both go_proto_library and java_proto_library declared.</p>
  <p>Now in <code>C.go</code>, I'm trying to build a <code>Bar</code> object, but I continuously got errors when trying to set the value for <code>Foo</code>. I could not import <code>A.proto</code> in <code>C.go</code>, as A does not have a go proto library. Would there be a way to reference/set value for <code>Foo</code> in C with only <code>B.proto</code> imported?</p>
  <p>Many thanks for any help!</p>