public com.google.protobuf.ByteString getDisplayNameBytes() {
      java.lang.Object ref = displayName_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        displayName_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Optional. Immutable. The user-generated meaningful display name of the
cached content.
</pre>

<code>
string display_name = 11 [(.google.api.field_behavior) = OPTIONAL, (.google.api.field_behavior) = IMMUTABLE];
</code>

@return The bytes for displayName.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/CachedContent.java