validateVersion(
                            prefix, "version", problems, errOn30, Version.V20, d.getVersion(), d.getManagementKey(), d);

                    /*
                     * TODO Extensions like Flex Mojos use custom scopes like "merged", "internal", "external", etc. In
                     * order to don't break backward-compat with those, only warn but don't error out.
                     */
                    validateEnum(

        "//tensorflow/dtensor/cc:dtensor_device_cc",
        "//tensorflow/dtensor/cc:tensor_layout",
        "//tensorflow/lite/c:common",
        "//tensorflow/lite/core/api",
        "//tensorflow/lite/delegates/flex:delegate",
        "//tensorflow/lite/kernels/internal:compatibility",
        "//tensorflow/lite/kernels:builtin_ops",
        "//tensorflow/lite/kernels:reference_ops",
        "//tensorflow/lite/schema:schema_fbs",

github.com/asaskevich/govalidator
https://github.com/asaskevich/govalidator
----------------------------------------------------------------
The MIT License (MIT)

Copyright (c) 2014-2020 Alex Saskevich

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal

  * You can now set `VolumeMount.Propagation` to `Bidirectional` to enable a particular mount for a container to propagate itself to the host or other containers.

* [alpha] Improve Flex volume deployment

  * Flex volume driver deployment is simplified in the following ways:

    * New driver files can now be automatically discovered and initialized without requiring a kubelet or controller-manager restart.