Usage: test-app --required-var=REQUIRED-VAR [flags]

Flags:
  -h, --help                Show context-sensitive help.
      --string-var="string-default"
                            ($STRING_VAR)
      --int-var=123         ($INT_VAR)
      --bool-var            ($BOOL_VAR)
      --duration-var=10s    ($DURATION_VAR)
      --required-var=REQUIRED-VAR
                            The config YAML file ($CONFIG_FILE)
