How to use the @zilliqa-js/core.EventEmitter function in @zilliqa-js/core

this.toAddr = normaliseAddress(params.toAddr);
    this.nonce = params.nonce;
    this.pubKey = params.pubKey;
    this.amount = params.amount;
    this.code = params.code || '';
    this.data = params.data || '';
    this.signature = params.signature;
    this.gasPrice = params.gasPrice;
    this.gasLimit = params.gasLimit;
    this.receipt = params.receipt;
    // public members
    this.provider = provider;
    this.status = status;
    this.toDS = toDS;
    this.blockConfirmation = 0;
    this.eventEmitter = new EventEmitter();
  }