How to use the @microsoft/api-extractor-model.ApiReturnTypeMixin.isBaseClassOf function in @microsoft/api-extractor-model

private _populateYamlFunctionLike(
    yamlItem: Partial,
    apiItem: ApiMethod | ApiMethodSignature | ApiConstructor | ApiFunction
  ): void {
    const syntax: IYamlSyntax = {
      content: apiItem.getExcerptWithModifiers()
    };
    yamlItem.syntax = syntax;

    if (ApiReturnTypeMixin.isBaseClassOf(apiItem)) {
      const returnType: string = this._linkToUidIfPossible(apiItem.returnTypeExcerpt.text);

      let returnDescription: string = '';

      if (apiItem.tsdocComment && apiItem.tsdocComment.returnsBlock) {
        returnDescription = this._renderMarkdown(apiItem.tsdocComment.returnsBlock.content, apiItem);
        // temporary workaround for people who mistakenly add a hyphen, e.g. "@returns - blah"
        returnDescription = returnDescription.replace(/^\s*-\s+/, '');
      }

      if (returnType || returnDescription) {
        syntax.return = {
          type: [returnType],
          description: returnDescription
        };
      }

_populateYamlFunctionLike(yamlItem, apiItem, parentYamlFile) {
        /** @type {IYamlSyntax} */
        const syntax = {
            content: apiItem.getExcerptWithModifiers()
        };
        yamlItem.syntax = syntax;

        if (ApiReturnTypeMixin.isBaseClassOf(apiItem)) {
            const returnType = this[kAdaptType](apiItem.returnTypeExcerpt, parentYamlFile);

            let returnDescription = '';

            if (apiItem.tsdocComment && apiItem.tsdocComment.returnsBlock) {
                // @ts-ignore
                returnDescription = this._renderMarkdown(apiItem.tsdocComment.returnsBlock.content, apiItem);
                // temporary workaround for people who mistakenly add a hyphen, e.g. "@returns - blah"
                returnDescription = returnDescription.replace(/^\s*-\s+/, '');
            }

            if (returnType || returnDescription) {
                syntax.return = {
                    type: [returnType],
                    description: returnDescription
                };

new DocTableCell({ configuration }, [
            new DocParagraph({ configuration }, [
              new DocCodeSpan({ configuration, code: apiParameter.parameterTypeExcerpt.text }),
            ]),
          ]),
          new DocTableCell({ configuration }, parameterDescription.nodes),
        ]),
      );
    }

    if (parametersTable.rows.length > 0) {
      output.appendNode(new DocHeading({ configuration: this._tsdocConfiguration, title: 'Parameters' }));
      output.appendNode(parametersTable);
    }

    if (ApiReturnTypeMixin.isBaseClassOf(apiParameterListMixin)) {
      const returnTypeExcerpt: Excerpt = apiParameterListMixin.returnTypeExcerpt;
      output.appendNode(
        new DocParagraph({ configuration }, [
          new DocEmphasisSpan({ configuration, bold: true }, [
            new DocPlainText({ configuration, text: 'Returns:' }),
          ]),
        ]),
      );

      output.appendNode(
        new DocParagraph({ configuration }, [
          new DocCodeSpan({ configuration, code: returnTypeExcerpt.text.trim() || '(not declared)' }),
        ]),
      );

      if (apiParameterListMixin instanceof ApiDocumentedItem) {

new DocTableCell({configuration}, [
            new DocParagraph({ configuration }, [
              new DocCodeSpan({ configuration, code: apiParameter.parameterTypeExcerpt.text })
            ])
          ]),
          new DocTableCell({configuration}, parameterDescription.nodes)
        ])
      );
    }

    if (parametersTable.rows.length > 0) {
      output.appendNode(new DocHeading({ configuration: this._tsdocConfiguration, title: 'Parameters' }));
      output.appendNode(parametersTable);
    }

    if (ApiReturnTypeMixin.isBaseClassOf(apiParameterListMixin)) {
      const returnTypeExcerpt: Excerpt = apiParameterListMixin.returnTypeExcerpt;
      output.appendNode(
        new DocParagraph({ configuration }, [
          new DocEmphasisSpan({ configuration, bold: true}, [
            new DocPlainText({ configuration, text: 'Returns:' })
          ])
        ])
      );

      output.appendNode(
        new DocParagraph({ configuration }, [
          new DocCodeSpan({ configuration, code: returnTypeExcerpt.text.trim() || '(not declared)' })
        ])
      );

      if (apiParameterListMixin instanceof ApiDocumentedItem) {