"    Input:  {
              data_uoa or uoa   - environment UOA to pre-load (see "ck show env")
              (tags)            - a combination of comma-separated tags to narrow down the search
              (or_tags)         - a combination of semicolon-separated and comma-separated tags to narrow down the search
              (tag_groups)      - independent groups of or_tags, separated by a space, refer to separate env entries
                                  that can be combined together: '--tag_groups=alpha,beta gamma,~delta epsilon;lambda,mu'
              (search_dict)     - require verbatim matches of some attributes
              (verbose)         - set to 'yes' to see the script that will be used to build the environment
              (shell_cmd)       - command line to run in the "environment-enriched" shell (make sure it is suitably quoted)
            }

    Output: {
              return       - return code =  0, if successful
                                         >  0, if error
              (error)      - error text if return > 0
            }
    Test:
        ck virtual env --tags=model,onnx,resnet --shell_cmd='echo $ML_MODEL_DATA_LAYOUT'

"