public com.google.protobuf.ByteString getSourceVmIdBytes() {
      java.lang.Object ref = sourceVmId_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        sourceVmId_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
The unique ID of the VM in the source.
The VM's name in vSphere can be changed, so this is not the VM's name but
rather its moRef id. This id is of the form vm-&lt;num&gt;.
</pre>

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

@return The bytes for sourceVmId.
java-vmmigration/proto-google-cloud-vmmigration-v1/src/main/java/com/google/cloud/vmmigration/v1/MigratingVm.java