code: public void deleteFromSchema(Mutation mutation, String cfName, long timestamp)
      {
          ColumnFamily cf = mutation.addOrGet(SystemKeyspace.SCHEMA_TRIGGERS_CF);
          int ldt = (int) (System.currentTimeMillis() / 1000);
  
          Composite prefix = CFMetaData.SchemaTriggersCf.comparator.make(cfName, name);
          cf.addAtom(new RangeTombstone(prefix, prefix.end(), timestamp, ldt));
      }
docs: Drop specified trigger from the schema using given mutation.
  
  @param mutation  The schema mutation
  @param cfName    The name of the parent ColumnFamily
  @param timestamp The timestamp to use for the tombstone