code: private String docKindOfArg(final NamedArgumentDefinition argumentDefinition) {
  
          // deprecated
          // required (common or otherwise)
          // common optional
          // advanced
          // hidden
  
          // Required first (after positional, which are separate), regardless of what else it might be
          if (argumentDefinition.isDeprecated()) {
              return "deprecated";
          }
          if (argumentDefinition.isControlledByPlugin()) {
              return "dependent";
          }
          if (!argumentDefinition.isOptional()) {
              return "required";
          }
          if (argumentDefinition.isCommon()) {  // these will all be optional
              return "common";
          }
          if (argumentDefinition.isAdvanced()) {
              return "advanced";
          }
          if (argumentDefinition.isHidden()) {
              return "hidden";
          }
          return "optional";
      }
docs: Return the argument kind (required, advanced, hidden, etc) of this argumentDefinition
  
  @param argumentDefinition
  @return