_getDebuggerConfigs(runtime, hostDir, workingDir, debugPort) {
    let vscodeConfigs;
    switch (runtime) {
    case 'nodejs8':
      vscodeConfigs = {
        'version': '0.2.0',
        'configurations': [
          {
            'name': 'Attach to Fun (Node.js 8)',
            'type': 'node',
            'request': 'attach',
            'address': 'localhost',
            'port': debugPort,
            'localRoot': `${hostDir}`,
            'remoteRoot': `${workingDir}`,
            'protocol': 'inspector',
            'stopOnEntry': false
          }
        ]
      };
      break;
    case 'python3':
      vscodeConfigs = {
        'version': '0.2.0',
        'configurations': [
          {
            'name': 'Attach to Fun (Python 3)',
            'type': 'python',
            'request': 'attach',
            'host': 'localhost',
            'port': debugPort,
            'pathMappings': [
              {
                'localRoot': `${hostDir}`,
                'remoteRoot': `${workingDir}`
              }
            ]
          }
        ]
      };
      break;
    default:
      break;
    }
    const configs = `
Debugging Configurations
## VS Code ##
${JSON.stringify(vscodeConfigs, null, 4)}
`;
    return configs;
  }
Return the configurations for debuggers, currently only vscode.

@param runtime the runtime of the function.
@param hostDir the local path of the function code.
@param workingDir the remote path on the container where the function locates.
@param debugPort the debug port for debugger to connect.
@returns {string} the configurations for debuggers.
@private