How to use the @microsoft/api-extractor-model.ApiItemKind.Function function in @microsoft/api-extractor-model

switch (apiItem.kind) {
      case ApiItemKind.Class:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} class` }));
        break;
      case ApiItemKind.Enum:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} enum` }));
        break;
      case ApiItemKind.Interface:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} interface` }));
        break;
      case ApiItemKind.Method:
      case ApiItemKind.MethodSignature:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} method` }));
        break;
      case ApiItemKind.Function:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} function` }));
        break;
      case ApiItemKind.Namespace:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} namespace` }));
        break;
      case ApiItemKind.Package:
        const unscopedPackageName: string = PackageName.getUnscopedName(apiItem.displayName);
        console.log(apiItem.displayName);
        output.appendNode(new DocHeading({ configuration, title: `${unscopedPackageName} package` }));
        break;
      case ApiItemKind.Property:
      case ApiItemKind.PropertySignature:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} property` }));
        break;
      case ApiItemKind.TypeAlias:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} type` }));

break;
      case ApiItemKind.Enum:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} enum` }));
        break;
      case ApiItemKind.Interface:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} interface` }));
        break;
      case ApiItemKind.Constructor:
      case ApiItemKind.ConstructSignature:
        output.appendNode(new DocHeading({ configuration, title: scopedName }));
        break;
      case ApiItemKind.Method:
      case ApiItemKind.MethodSignature:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} method` }));
        break;
      case ApiItemKind.Function:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} function` }));
        break;
      case ApiItemKind.Model:
        output.appendNode(new DocHeading({ configuration, title: `API Reference` }));
        break;
      case ApiItemKind.Namespace:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} namespace` }));
        break;
      case ApiItemKind.Package:
        console.log(`Writing ${apiItem.displayName} package`);
        const unscopedPackageName: string = PackageName.getUnscopedName(apiItem.displayName);
        output.appendNode(new DocHeading({ configuration, title: `${unscopedPackageName} package` }));
        break;
      case ApiItemKind.Property:
      case ApiItemKind.PropertySignature:
        output.appendNode(new DocHeading({ configuration, title: `${scopedName} property` }));

collectedData,
          apiMethodSignature.excerptTokens,
          apiMethodSignature.excerpt.tokenRange
        );

        if (apiMethodSignature.tsdocComment) {
          if (apiMethodSignature.tsdocComment.deprecatedBlock) {
            tableRowJson.deprecated = true;
          }

          tableRowJson.description += renderDocNodeWithoutInlineTag(apiMethodSignature.tsdocComment.summarySection);
        }
        interfaceTableRowJson.push(tableRowJson);
        break;
      }
      case ApiItemKind.Function: {
        break;
      }
      case ApiItemKind.Class: {
        break;
      }
    }
  }

  tableJson.members = interfaceTableRowJson;

  return tableJson;
}

case ApiItemKind.Package:
        yamlItem.type = 'package';
        break;
      case ApiItemKind.Property:
      case ApiItemKind.PropertySignature:
        const apiProperty: ApiPropertyItem = apiItem as ApiPropertyItem;
        if (apiProperty.isEventProperty) {
          yamlItem.type = 'event';
        } else {
          yamlItem.type = 'property';
        }
        this._populateYamlProperty(yamlItem, apiProperty);
        break;

      case ApiItemKind.Function:
        yamlItem.type = 'function';
        this._populateYamlFunctionLike(yamlItem, apiItem as ApiFunction);
        break;

      default:
        throw new Error('Unimplemented item kind: ' + apiItem.kind);
    }

    if (apiItem.kind !== ApiItemKind.Package && !this._shouldEmbed(apiItem.kind)) {
      const associatedPackage: ApiPackage | undefined = apiItem.getAssociatedPackage();
      if (!associatedPackage) {
        throw new Error('Unable to determine associated package for ' + apiItem.displayName);
      }
      yamlItem.package = this._getUid(associatedPackage);
    }