public Entity RetrieveLookupByAttribute(string attrName, object attrValue)
{
ThrowIf.Argument.IsNullOrEmpty(attrName, "attrName");
var targetEntity = this.LookupTargetEntityName;
if (string.IsNullOrEmpty(targetEntity))
{
throw new InvalidPluginExecutionException("Field mapping error, lookup target entity is empty.");
}
var targets = OrgService.RetrieveMultipleByAttribute(targetEntity, attrName, attrValue);
return(targets.FirstOrDefault());
}