code: function BlockTemplate(options) {
    if (!(this instanceof BlockTemplate))
      return new BlockTemplate(options);
  
    this.prevBlock = encoding.NULL_HASH;
    this.version = 1;
    this.height = 0;
    this.time = 0;
    this.bits = 0;
    this.target = encoding.ZERO_HASH;
    this.locktime = 0;
    this.mtp = 0;
    this.flags = 0;
    this.coinbaseFlags = DUMMY;
    this.witness = false;
    this.address = new Address();
    this.reserve = new Address();
    this.sigops = 400;
    this.weight = 4000;
    this.interval = 210000;
    this.fees = 0;
    this.tree = new MerkleTree();
    this.commitment = encoding.ZERO_HASH;
    this.left = DUMMY;
    this.right = DUMMY;
    this.items = [];
  
    if (options)
      this.fromOptions(options);
  }
docs: Block Template
  @alias module:mining.BlockTemplate
  @constructor
  @param {Object} options