I have to make callout from salesforce to external sysytem. need to send a file as xml (request body to POSt method) And i have object for this and all the fields i am querying from this object called Clientdetails. not sute how to convert as xml fil for Rest service <message><data><result><order_code>8798</order_code><result_code>pp</result_code><units>pp</units><value>3</value><reference>2-4</reference><date>2017-12-14</date><normalcy>N</normalcy><facility>OO\^Example Labs MMD\^26901 Rod Hills Road\^Calabasas Hills\^CA\^91301\^Dr. Test, MD</facility></result><result><order_code>8798</order_code><result_code>pp</result_code><units>pp</units><value>3</value><reference>2-4</reference><date>2017-12-14</date><normalcy>N</normalcy><facility>99\^Example Service MMD\^26901 Rod Hills Road\^Calabasas Hills\^CA\^91301\^Dr. Test, MD</facility></result></data></message>