def send_bitcoins(from, send_params, fees = nil, mode = 'broadcast')
      colored_outputs = get_unspent_outputs([from])
      btc_transfer_specs = send_params.map{|param|
        OpenAssets::Transaction::TransferParameters.new(colored_outputs, param.to, from, param.amount)
      }
      tx = create_tx_builder.transfer_btcs(btc_transfer_specs, fees.nil? ? @config[:default_fees]: fees)
      tx = process_transaction(tx, mode)
      tx
    end
def send_bitcoins(from, send_params, fees = nil, mode = 'broadcast')
      colored_outputs = get_unspent_outputs([from])
      btc_transfer_specs = send_params.map{|param|
        OpenAssets::Transaction::TransferParameters.new(colored_outputs, param.to, from, param.amount)
      }
      tx = create_tx_builder.transfer_btcs(btc_transfer_specs, fees.nil? ? @config[:default_fees]: fees)
      tx = process_transaction(tx, mode)
      tx
    end
Creates a transaction for sending multiple bitcoins from an address to others.
 @param[String] from The address to send the bitcoins from.
 @param[Array[OpenAssets::SendBitcoinParam]] send_params The send information(amount of satoshis and to).
 @param[Integer] fees The fees in satoshis for the transaction.
 @param[String] mode 'broadcast' (default) for signing and broadcasting the transaction,
 'signed' for signing the transaction without broadcasting,
 'unsigned' for getting the raw unsigned transaction without broadcasting"""='broadcast'
 @return[Bitcoin::Protocol:Tx] The resulting transaction.