How to use the oas-validator.validate function in oas-validator

let resultStr2 = yaml.stringify(result); // FIXME dropped 'noRefs:true' here
                should(resultStr).not.be.exactly('{}','Result should not be empty');
                should(resultStr).equal(resultStr2,'Result should have no object identity ref_s');
            }
            catch (ex) {
                if (options.verbose>1) {
                    fs.writeFileSync('./debug.yaml',resultStr,'utf8');
                    console.warn('Result dumped to debug.yaml fixed.yaml');
                    let fix = reref(result);
                    fs.writeFileSync('./fixed.yaml',yaml.stringify(fix),'utf8');
                }
                should.fail(false,true,'Result cannot be represented safely in YAML');
            }
        }

        validator.validate(result, options)
        .then(function(options){
            finalise(null,options);
        })
        .catch(function(ex){
            finalise(ex,options);
        });
    }
    catch (ex) {
        console.warn(common.colour.normal + options.file);
        console.warn(common.colour.red + (options.context.length ? options.context.pop() : 'No context')+ '\n' + ex.message);
        if (ex.stack && ex.name !== 'AssertionError' && ex.name !== 'CLIError') {
            console.warn(ex.stack);
        }
        options.valid = !options.expectFailure;
        finalise(ex, options);
    }

let editor = vscode.window.activeTextEditor;
    if (!editor) {
        vscode.window.showWarningMessage('You must have an open editor window to validate an OpenAPI document');
        return; // No open text editor
    }

    if (resolve && editor.document.isUntitled) {
        vscode.window.showWarningMessage('Document must be saved in order to resolve correctly');
        return; // No open text editor
    }

    let text = editor.document.getText();
    try {
        let options = { lint: lint, resolve: resolve, fatal: true, source: editor.document.fileName };
        let obj = yaml.parse(text);
        validator.validate(obj, options)
        .then(function(){
            vscode.window.showInformationMessage('Your OpenAPI document is '+(lint ? 'excellent!' : 'valid.'));
        })
	    .catch(function(ex){
            dc.delete(editor.document.uri);
            const diagnostics = [];
            let range; // TODO
            diagnostics.push(new vscode.Diagnostic(range, ex.message, vscode.DiagnosticSeverity.Error));
            for (let warning of options.warnings||[]) {
                diagnostics.push(new vscode.Diagnostic(range, warning.message + ' ' + warning.ruleName, vscode.DiagnosticSeverity.Warning));
            }
            dc.set(editor.document.uri, diagnostics);
	    });
    }
    catch (ex) {
        vscode.window.showErrorMessage('Could not parse OpenAPI document as JSON or YAML!');

options.format = 'asyncapi_1';
        api.asyncapi = api.version;
        delete api.version;
        recurse(api,{},function(obj,key,state){
            if (key === 'asyncapi_servers_variables') {
                obj.variables = obj.asyncapi_servers_variables;
                delete obj.asyncapi_servers_variables;
            }
        });
    }
}

if (options.format === 'openapi_3') {
    var options = {laxRefs:true,resolve:true,source:options.source,convert:options.convert};
    try {
        openapi3.validate(api, options, function(err, opts) {
            if (err) {
                return callback(err, err.options||opts||options);
            }
            options.converted = options.openapi||api;
            options.message = 'Valid openapi 3.0.x';
            options.context = [api.info.version + ' ' +
            (api.servers && api.servers.length ? api.servers[0].url : 'Relative')];
            callback(null, options);
        });
    }
    catch (ex) {
        var context = options.context.pop();
        options.context = [context];
        callback(ex, options);
    }
}