code: func NewMsgGetCFHeaders(filterType FilterType, startHeight uint32,
  	stopHash *chainhash.Hash) *MsgGetCFHeaders {
  	return &MsgGetCFHeaders{
  		FilterType:  filterType,
  		StartHeight: startHeight,
  		StopHash:    *stopHash,
  	}
  }
docs: // NewMsgGetCFHeaders returns a new bitcoin getcfheader message that conforms to
  // the Message interface using the passed parameters and defaults for the
  // remaining fields.