docs: function ScriptManager() {
  
    // child process
    this.ps = null;
  
    // script execution limit in milliseconds
    this._limit = 5000;
  
    // flag determining if a script is busy executing
    this._busy = false;
  
    // flag determining if script execution issued
    // any write commands
    this._written = false;
  
    // currently executing script name
    this._script = null;
  
    // injected reference to the command handlers
    this._commands = {};
  
    // script limit timeout listener
    this.onTimeout = this.onTimeout.bind(this);
  }