code: def get_field_errors(node):
          
          assert node.Name == 'securityData' and not node.IsArray
          nodearr = node.GetElement('fieldExceptions')
          if nodearr.NumValues > 0:
              secid = XmlHelper.get_child_value(node, 'security')
              errors = XmlHelper.as_field_error(nodearr, secid)
              return errors
          else:
              return None
docs: return a list of FieldErrors if the specified securityData element has field errors