internal MavlinkQueryEnumerator(MavlinkLog log, LogItemSchema schema, CancellationToken token)
 {
     this.log    = log;
     this.schema = schema;
     this.token  = token;
     this.log.AddQuery(this);
 }
 internal MavlinkQuery(MavlinkLog log, LogItemSchema schema, CancellationToken token)
 {
     this.log    = log;
     this.schema = schema;
     this.token  = token;
 }