def retrieve_transactions(query = nil, transaction_id = nil)
      headers.merge!(params: query) if query
      url = "#{API_BASE}/transaction/#{transaction_id}"
      begin
        response = RestClient.get(url, headers)
        JSON.parse(response)
      rescue RestClient::Unauthorized => error
        raise Bitpagos::Errors::Unauthorized.new(error.message)
      end
    end
def retrieve_transactions(query = nil, transaction_id = nil)
      headers.merge!(params: query) if query
      url = "#{API_BASE}/transaction/#{transaction_id}"
      begin
        response = RestClient.get(url, headers)
        JSON.parse(response)
      rescue RestClient::Unauthorized => error
        raise Bitpagos::Errors::Unauthorized.new(error.message)
      end
    end
Hits the Bitpagos transaction API, returns a hash with results

 @param [String] State (Pending, Waiting, Completed, Partially Paid)
 @param [String] Transaction ID
 @return [Hash]