docs: def drop_file(self, filename, **kwargs):
          """ removes the passed in file from the connected triplestore
  
          args:
              filename: the filename to remove
          """
          log.setLevel(kwargs.get("log_level", self.log_level))
          conn = self.__get_conn__(**kwargs)
          result = conn.update_query("DROP GRAPH %s" % \
                                     getattr(__NSM__.kdr, filename).sparql,
                                     **kwargs)
          # Remove the load time from the triplestore
          conn.update_query("""
                  DELETE
                  {{
                     GRAPH {graph} {{ ?file dcterm:modified ?val }}
                  }}
                  WHERE
                  {{
                      VALUES ?file {{ kdr:{file} }} .
                      OPTIONAL {{
                          GRAPH {graph} {{?file dcterm:modified ?val }}
                      }}
                  }}""".format(file=filename, graph="kdr:load_times"),
                  **kwargs)
          self.loaded.remove(filename)
          log.warning("Dropped file '%s' from conn %s", filename, conn)
          return result