code: function Converter() {
  
    // Validate arguments
    if (arguments.length === 1) {
  
      this._bl = 2;
  
      if (typeof arguments[0] !== "function")
        throw new TypeError("Converter requires at least a callback function");
      else
        this._fx = arguments[0];
  
    } else if (arguments.length >= 2) {
  
      this._bl = arguments[0];
      if (this._bl !== 1 && this._bl !== 2 && this._bl !== 4)
        throw new TypeError("Prefix length must be 1, 2 or 4");
  
      if (typeof arguments[1] !== "function")
        throw new TypeError("Converter requires a callback function");
      else
        this._fx = arguments[1];
  
    } else {
      throw new Error("cannot construct a converter without a callback");
    }
  
    this.flush();
  }
docs: Takes in a series of Buffers and calls back whenever a fixed-length
  message has been completely processed.
  
  @param {Integer} [prefixLength] - The length in bytes of the size prefix.
  This argument is optional. The default length is 2 bytes, but can also be 1
  or 4 bytes.
  
  @param {Function} callback - This will be called every time a new message has
  been completely processed.