How to use the surya.describe function in surya

let files;

        if(solidityVAConfig.tools.surya.input.contracts=="workspace"){
            await vscode.workspace.findFiles("**/*.sol",'**/node_modules', 500)
                .then(uris => {
                    files = uris.map(function (uri) {
                        return uri.fsPath;
                    });
                });
        } else {
            files = [document.uri.fsPath, ...Object.keys(this.g_parser.sourceUnits)];  //better only add imported files. need to resolve that somehow
        } 

        switch(command) {
            case "describe":
                ret = surya.describe(files, {}, true);
                vscode.workspace.openTextDocument({content: ret, language: "markdown"})
                    .then(doc => vscode.window.showTextDocument(doc, vscode.ViewColumn.Beside));
                break;
            case "graph":
                ret = surya.graph(args || files, {colorScheme: suryaDefaultColorSchemeDark});
                //solidity-va.preview.render.markdown
                vscode.workspace.openTextDocument({content: ret, language: "dot"})
                    .then(doc => {
                        if(solidityVAConfig.preview.dot){
                            vscode.commands.executeCommand("interactive-graphviz.preview.beside", {document: doc, content:ret, callback:null})
                            .catch(error =>{
                                vscode.commands.executeCommand("graphviz.previewToSide", doc.uri)
                                .catch(error => {
                                    //command not available. fallback open as text and try graphviz.showPreview
                                    vscode.window.showTextDocument(doc, vscode.ViewColumn.Beside)
                                        .then(editor => {