code: def get_validation_errors(self, xml_input):
          
          errors = []
          try:
              parsed_xml = etree.parse(self._handle_xml(xml_input))
              self.xmlschema.assertValid(parsed_xml)
          except (etree.DocumentInvalid, etree.XMLSyntaxError), e:
              errors = self._handle_errors(e.error_log)
          except AttributeError:
              raise CannotValidate('Set XSD to validate the XML')
          return errors
docs: This method returns a list of validation errors. If there are no errors
          an empty list is returned