code: function (callback) {
  
      "use strict";
  
      this.filename ="";
      this.lastLine = "";
      this.entries = { };
      this.types = {};
      this.typesRev = {};
      this.callback = callback;
  
  
      this.curLine = "";
  
      this.bad_STEP_file = false;
  
      this.status = waiting_file_type;
  
      this.header = []; // un parsed header
  
  }
docs: something like # 123 = ... 
  this class reads and loads a raw step file in  memory
  
  @param callback
  @constructor