public com.google.protobuf.ByteString getSessionIdBytes() {
      java.lang.Object ref = sessionId_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        sessionId_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Required if
[allow_missing_ids][google.cloud.talent.v4.RequestMetadata.allow_missing_ids]
is unset or `false`.

A unique session identification string. A session is defined as the
duration of an end user's interaction with the service over a certain
period.
Obfuscate this field for privacy concerns before
providing it to the service.

Note that any improvements to the model for a particular tenant site rely
on this field being set correctly to a unique session ID.

The maximum number of allowed characters is 255.
</pre>

<code>string session_id = 2;</code>

@return The bytes for sessionId.
java-talent/proto-google-cloud-talent-v4/src/main/java/com/google/cloud/talent/v4/RequestMetadata.java