code: def get_span_kind_as_int(self, span):
          
          kind = None
          if "span.kind" in span.tags:
              if span.tags["span.kind"] in self.entry_kind:
                  kind = 1
              elif span.tags["span.kind"] in self.exit_kind:
                  kind = 2
              else:
                  kind = 3
          return kind
docs: Will retrieve the `span.kind` tag and return the appropriate integer value for the Instana backend or
              None if the tag is set to something we don't recognize.
  
          :param span: The span to search for the `span.kind` tag
          :return: Integer