def exists?(details)
      !@wallet.txns.find { |t| t.details.start_with?("#{PREFIX} ") && t.details == details }.nil?
    end
def exists?(details)
      !@wallet.txns.find { |t| t.details.start_with?("
    end
def exists? ( details ) ! @wallet . txns . find { | t | t . details . start_with? ( "#{PREFIX} " ) && t . details == details } . nil? end
Check whether this tax payment already exists in the wallet.
Check whether this tax payment already exists in the wallet .